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One way some animals support life: Parasites

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One way some animals support life: Parasites

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Hundreds to thousands of tiny crustaceans live on each right whale, eating algae that settles on their skin. (© Michael Moore/Woods Hole Oceanographic Institution)

Cetaceans include the largest living animals on the planet, but some of the smallest can be found living on and in whales, dolphins, and porpoises. Small crustaceans called whale lice live in folds and rough patches of their skin, as well as in their lesions and nostrils. Most whale louse species have an exclusive corresponding cetacean species that acts as the host for their entire life cycle. Male and female sperm whales even have different unique lice species that they host.

Barnacles mooch off of whales in a commensal relationship—hitching a ride on their backs. The barnacles don’t harm the whale but take advantage of the moving home that brings meals directly to them. Remora fish also take advantage of the ride, attaching to the large mammals with a modified fin. They don’t seem to harm cetaceans—research indicates that they likely help whales remove other external parasites, although any substantial benefit remains unclear. Some seabird and fish species that follow whales take advantage of these leftovers.

A large diversity of internal parasites also infest cetaceans. A variety of parasitic worm species can be found in the blubber, intestines, stomach, liver, and lungs of whales. One roundworm species lives in the placenta of sperm whales and reaches lengths of over eight meters, and pygmy sperm whales host a similarly long roundworm in the tissue under the whale’s skin.

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When we think of whales, the enormous ones that filter tiny plankton from seawater with their baleen-fringed upper jaw often come first to mind (like the right whale in the picture above). But cetaceans also include dolphins, porpoises and other toothed whales, and in total contain more than 80 different species.

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Lots of marine ecosystem and animal info

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Lots of marine ecosystem and animal info

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Did you know that corals not only grow in coastal reefs but in the deep ocean as well? This overview dives into everything to know about deep-sea corals.

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Octopuses are sea animals famous for their rounded bodies, bulging eyes, and eight long arms. They live in all the world's oceans but are especially abundant in warm, tropical waters. Octopuses, like their cousin, the squid, are often considered "monsters of the deep," though some species, or types, occupy relatively shallow waters.

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Octopuses are sea animals famous for their rounded bodies, bulging eyes, and eight long arms. They live in all the world's oceans but are especially abundant in warm, tropical waters. Octopuses, like their cousin, the squid, are often considered "monsters of the deep," though some species, or types, occupy relatively shallow waters.

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Welcome to Britannica School , a safe, up-to-date, and age-appropriate information resource for Primary, Middle and Secondary School.

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A mollusk is a kind of animal with a soft body. Most mollusks have a hard shell that protects the body. There are more than 100,000 species, or types, of mollusk. Octopuses,...

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A simple Antarctic food chain is the secret to the success of the baleen whales - keep the chain short and transfer as much energy as possible as efficiently as possible.

Whales are the largest animals ever to have lived, larger even than the largest dinosaurs. There are two reasons that they have managed to attain such enormous size - well over a hundred tonnes for the largest blue whales and nearing this amount for some other whale species.

1/ They live in the oceans and so the buoyancy of the water can support their great bulk rather than having to be propped up on land by legs and muscles. As with most other mammals, the density of a whale is very close to that of water.

2/ Whales tap the food chain low down - close to the producers, there are few steps and so little energy is lost meaning more is available to the whales, so they are able to grow to enormous sizes. The higher up a food chain you get, the lower the biomass of animals (that is number of animals multiplied by their weight) because there are more steps and so more energy is lost. The more steps in a chain means less food available at the top, no more than 10% is ever passed on from one step to the next, often much less.

Antarctic Ocean Food Web

The Antarctic Food Web is relatively simple compared to ecosystems in other parts of the world. There are fewer different species, but greater numbers of individuals of each. The second most numerous large mammal in the world (after man) is the crab-eater seal, an archetypal Antarctic animal.

A key part of the Antarctic food web are krill small shrimp-like crustaceans that the great majority of Antarctic animals, seal, whales, penguins and other birds, fish etc. feed upon.
Phytoplankton - The Producers in Antarctic Food Chains
There are few land plants in Antarctica, all the large animals including the ones that come onto land like seals, penguins and other birds take their food from the sea. The producers in Antarctic food chains are tiny single celled plants known collectively as phytoplankton that float in the upper layer of the sea though they can grow at depths down to about 100m.

Assorted phytoplankton, these are about 20,000 larger than life size

There are many different species and types of phytoplankton, the two largest groups are Diatoms and Dinoflagellates, they are from 2-2000 micrometers in size, by comparison the width of a human hair is in the region of 100 micrometers.

Diatoms are made of two (di) external silica shells that fit together like a small box. Dinoflagellates have a flagellum a whip-like "tail" that they can use to move about.

Food chain: A sequence of organisms starting with a producer (usually a plant), followed by the animal that eats the plant, then an animal that eats that animal and so on to the "top carnivore" an animal that eats others but is not killed and eaten by any other. Though everything eventually gets "eaten" by decomposers when it dies by some other cause. The arrows always point to the animal that does the eating and from the organism that gets eaten, more specifically they indicate the flow of energy.

Food web: A complex combination of a number of animals and plants in an ecosystem or habitat that shows what eats what and what gets eaten by what. A food web shows a more accurate picture as in reality it is rare for anything to just eat one kind of food.

Plankton: organisms that live in the top layers of a body of water, whether sea, lake, pond, river etc. Plankton are at the mercy of the currents and movement of the water. Some plankton dwellers can move about within the water column, up and down, but drift where the tides and currents take them.

Phytoplankton: Phyto- plant, Plankton - see above. These are the tiny plants that capture the energy of the sun and turn it into food, they are the Producers of the Antarctic food web. As they are so tiny, they can divide and grow very quickly in response to the more intense and longer lasting light of the summer months.

Zooplankton; Zoo - animal, Plankton - see above. These are the tiny (and not so tiny) animals that feed directly on the phytoplankton, In Antarctica they are often krill which provide the food for most of all the larger animals.

Producer : An organism that produces food. Usually a green plant, anything from microscopic algae (as in phytoplankton) to a tree. The raw materials are sunlight for energy, with carbon dioxide and water providing the main raw materials for growth. Producers drive all food webs and chains. At each step along the chain energy is lost, only 10% or often much less is passed on between steps.

: An organism that eats food in the form of other organisms, plants, animals or a mixture of the two. If the consumer eats plants it is called a primary consumer as it is the first consumer in the food chain. If it eats an animal that itself is a consumer it is a secondary consumer as the second consumer in the food chain. In the Antarctic food chain krill are primary consumers and baleen whales, penguins, seals and many kinds of fish and other birds are secondary consumers when feeding on krill. Many animals are a mixture of primary, secondary, tertiary (3rd) and quaternary (4th) consumers as they eat a variety of prey.

The original nursery rhyme "Fleas".

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A simple Antarctic food chain is the secret to the success of the baleen whales - keep the chain short and transfer as much energy as possible as efficiently as possible. Whales are the largest animals ever to have lived, larger even than the largest dinosaurs.

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Humpback whales are enormous creatures - about the size of a school bus. They are known for their haunting and melodic songs and for breaching the water with amazing acrobatic abilities.

Humpbacks don't normally have a hump on their backs; the name comes from the large hump that forms when they arch their backs before making a deep dive into the ocean. The scientific name, Megaptera novaeangliae, means "big-winged New Englander" because the population that swam off New England was the best known to Europeans, according to the National Oceanic and Atmospheric Administration (NOAA).

Size

Humpback whales are not the biggest whales - that's the blue whale. Humpbacks can grow to 60 feet (18 meters) long, and they can weigh a whopping 40 tons (about half the size of a blue whale), according to the NOAA. Their flippers can grow up to 16 feet (5 m) long, which is the largest appendage in the world. Their tails are also massive and grow up to 18 feet (5.5 m) wide. Like most whales, females are larger than males.

Humpbacks' heads are broad and rounded and covered with knobs, called tubercles. Each knob contains at least one stiff hair, according to the American Cetacean Society (ACS). The purpose of the hairs is not known, but it is thought that they may be motion detectors.

Humpbacks are black on the upper (dorsal) side and mottled black and white on the under (ventral) side. Ventral pleats run from the tip of the lower jaw to the belly, according to the ACS. They have a dorsal fin on their backs. The shape and color pattern on the dorsal fin and flukes is unique to each individual, like human fingerprints. That discovery has helped researchers identify, catalog and monitor humpback whale migration, population size, sexual maturity and behavior patterns.

Habitat

Humpbacks roam all over the world, but exactly where they may be found depends on the time of year. In the summer, many humpbacks spend their time in high-latitude feeding areas such of the Gulf of Alaska or the Gulf of Maine, according to the NOAA. During the winter, they swim to the warm waters closer to the Equator, around Hawaii, South America and Africa.

The exception is the humpbacks that live in the Arabian Sea. They stay there year-round, eating and mating all in the same area, according to the ACS.

(Image credit: Opération cétacés)

Habits

Humpbacks typically travel alone or in small groups, called pods, consisting of two or three whales, according to Whale Facts. When together, they communicate with each other and travel together, and moms and their young even touch fins as a possible sign of endearment. Sometimes they even help each other hunt.

Humpback whales migrate farther than any other mammal on Earth, according to the NOAA. They can travel around 3,000 miles (5,000 kilometers) between their breeding and feeding grounds on a regular basis. The longest ever recorded migration was 11,706 miles (18,840 km), a trip that went from American Samoa to the Antarctic Peninsula.

Breaching

Humpbacks often propel themselves above the water and then splash back down, according to National Geographic. This is called breaching. Some scientists think that they may do this to splash off parasites, but they may just do it because it's fun.

They also slap the water with their tails or flippers, according to the NOAA. These behaviors may be used to communicate with one another. They may also be used to show dominance and health during mating season, according to Whale Facts.

Whale songs

Humpback whales are known for their haunting songs, which are complex sequences of moans, howls and cries that often continue for hours, according to National Geographic. Only male whales sing, so scientists think they are trying to attract potential mates.

A male may sing for hours, repeating the song several times. All males in a population sing the same song, but the songs of each population are different. For example, whales in the North Atlantic sing one song, while whales in the North Pacific sing another song, according to the NOAA. Songs gradually change from year to year.

Songs can be heard 20 miles (30 km) away, according to the NOAA. The whale sounds typically have an audio frequency between 80 and 4,000 hertz, according to National Geographic. In 2015, researchers reported hearing humpback vocalizations around 40 hertz. The low limit for human hearing is 20 hertz.

But these marine giants don't just bellow out loud songs. Turns out, they also have "indoor voices" when the situations calls for it, according to a study published April 25, 2017, in the journal Functional Ecology. The researchers found that during their migrations of calves and their mothers to feeding grounds, the young ones made very quiet vocalizations; these calls were about 40 decibels quieter than those created by singing whales and up to 70 decibels lower than social vocalizations of adult humpback whales. The researchers suspect the "whale whispering" may be a way for the mother-calf pairs to stay under the radar of nearby killer whales.

Diet

Humpback whales are baleen whales. Rather than teeth, they have 270 to 400 fringed overlapping plates hanging down from each side of the upper jaw, called baleen plates. The plates are made of keratin, which is the same thing human hair and nails are made of. Baleen plates are black and about 30 inches (76 cm) long, according to the NOAA.

Humpbacks mostly dine on small fish, krill (tiny crustaceans) and plankton. To eat prey, they take large gulps of water. Below the mouth are 12 to 36 throat grooves that expand to hold the water. The baleens filter the water, and the two blowholes on the whale's back expel the water. The fish and other goodies remain in the whale for digestion.

These whales hunt and feed in the summer, and they will fast during mating season and live off the blubber reserves so they can focus on migration and mating, according to Whale Facts. A hunting method unique to humpbacks is called bubble netting. Humpbacks hunt in groups and use air bubbles to herd, corral or disorient fish. Humpbacks can eat up to 3,000 lbs. (1,360 kilograms) of food per day, according to the NOAA.

Offspring

A female humpback has a baby every two to three years. She carries her young for a gestation period of about 12 months, according to the ACS. Babies, called calves, are born live, like most mammals. The newborns are between 10 and 15 feet (3 to 4.5 m) long and weigh up to a ton (907 kg).

The calves nurse for almost a year. Their mother's milk is 45 to 60 percent fat content, according to the ACS. Calves can drink about 158 gallons (600 liters) of milk per day. Though they double their length in the first year, calves keep growing until they are 10 years old.

Humpbacks live around 50 years, according to the NOAA.

Classification/taxonomy

Humpbacks are one of 12 species of baleen whales, characterized by their baleen plates and paired blowholes, according to NOAA Fisheries. They are also called rorqual whales. Rorqual whales are relatively streamlined and have pointed heads and fins. They can be distinguished from other whales by the deep grooves along their throats.

Here is the taxonomy information for humpback whales, according to the Integrated Taxonomic Information System (ITIS):

Kingdom: Animalia Subkingdom: Bilateria Infrakingdom: Deuterostomia Phylum: Chordata Subphylum: Vertebrata Infraphylum: Gnathostomata Superclass: Tetrapoda Class: Mammalia Subclass: Theria Infraclass: Eutheria Order: Cetacea Suborder: Mysticeti Family: Balaenopteridae Genus: Megaptera Species: Megaptera novaeangliae

(Image credit: © Dr Ingrid Visser, Orca Research Trust)

Conservation status

The International Union for Conservation of Nature (IUCN) classifies humpbacks as least concern on its Red List of Threatened Species. However, as recently as 1988, humpback whales were listed as endangered. Populations have recovered, to between 30,000 and 40,000, which is about 30 to 35 percent of the population in 1940, according to the American Cetacean Society. The IUCN has a higher estimate of around 60,000 animals.

Commercial whaling of humpback whales is prohibited by the International Whaling Commission. Nevertheless, some humpbacks are still hunted, for subsistence purposes, in Greenland. Native people are allowed to kill a limited number of whales because whaling is a major part of their culture, according to Whale Facts. Norway, Iceland and Russia kill large numbers of whales each year. Japan also continues to hunt humpbacks, for scientific reasons.
Additional reporting by Reference Editor Tim Sharp. Follow him on Twitter Additional resources@TimothyASharp.

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Alina Bradford - Live Science Contributor

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Humpback whales are enormous creatures - about the size of a school bus. They are known for their haunting and melodic songs and for breaching the water with amazing acrobatic abilities. Humpbacks don't normally have a hump on their backs; the name comes from the large hump that forms when they arch their backs before making a deep dive into the ocean.

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College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, AK, United States

Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States

Texas Marine Mammal Stranding Network, Galveston, TX, United States

Accademia del Leviatano, V.le dell'Astronomia 19, Rome, Italy

Mysticetus LLC, Preston, WA, United States

Department of Natural Sciences, University of Alaska Southeast, Juneau, AK, United States

The whale-watching industry in Juneau, Alaska relies primarily on the presence of North Pacific humpback whales ( Megaptera novaeangliae). To meet demands from the rapidly growing tourism industry, the number of whale-watching vessels in this region has tripled over the last 18 years. As a result, increased vessel presence could have negative effects on humpback whales, ranging from short-term behavioral disturbance to long-term impacts. The current humpback whale viewing regulations are outdated and may not be as effective as they were 18 years ago, when both the whale-watching industry and humpback whale population were smaller. The present study assessed how humpback whale movement and behavioral patterns were affected by (1) vessel presence and number of vessels present, and (2) time spent in the presence of vessels. The study also determined how humpback whale behavioral state transitions were affected by vessel presence. A total of 201 humpback whale focal follows were conducted during summer 2016 and 2017. Based on linear mixed effects models, whales in the presence (vs. absence) of vessels exhibited 38.9% higher deviation in linear movement ( p = 0.001), 6.2% increase in swimming speed ( p = 0.047) and a 6.7% decrease in inter-breath intervals (IBI) ( p = 0.025). For each additional vessel present, deviation increased by 6.2% ( p = 0.022) and IBI decreased by 3.4% ( p = 0.001). As time spent in the presence of vessels increased, respiration rate increased ( p = 0.011). Feeding and traveling humpback whales were likely to maintain their behavioral state regardless of vessel presence, while surface active humpback whales were likely to transition to traveling in the presence of vessels. These short-term changes in movement and behavior in response to whale-watching vessels could lead to cumulative, long-term consequences, negatively impacting the health and predictability of the resource on which the industry relies. Current formal vessel approach regulations and voluntary guidelines should be revisited to reduce vessel pressure and mitigate potential negative effects of this growing whale-watching industry.

Introduction

Whale watching has been the world's fastest growing wildlife-based activity since its inception in the 1950's ( Hoyt and Parsons, 2014). Global whale-watching tourism opportunities have grown concomitantly with the recovery of many whale populations from historic whaling pressure ( Best, 1993; O'Connor et al., 2009). More than 13 million people in 119 countries engaged in whale-watching activities in 2008, yielding a global annual economic value of $2.1 billion, including $1 billion in revenue in the United States alone ( O'Connor et al., 2009). As a non-consumptive use of cetaceans, whale watching is often labeled as "eco-friendly," "green" or "sustainable" tourism. However, as the industry grows globally and the number of human-whale interactions increases, the whale-watching industry could be exploiting the resource on which they rely ( Parsons, 2012; Cressey, 2014).

There is mounting evidence that whale watching can lead to negative effects ranging from short-term behavioral changes that disrupt life functions (e.g., feeding) to long-term consequences such as declines in physical fitness and habitat alteration ( Lusseau and Bejder, 2007). In the presence of whale-watching vessels, whales have exhibited short-term behavioral changes including alteration of swimming speed and direction ( Scheidat et al., 2004), diving and foraging patterns ( Stamation et al., 2010; Christiansen et al., 2013b), aerial behaviors ( Stamation et al., 2010; Di Clemente et al., 2018), resting patterns ( Lusseau, 2003; Lundquist et al., 2012; Steckenreuter et al., 2012), group size and cohesion ( Steckenreuter et al., 2012), and acoustic communication ( Sousa-Lima and Clark, 2008). If short-term avoidance behaviors by whales (e.g., traveling at higher speeds, frequent changes in direction, movement away from whale-watching vessels) negatively affects body maintenance behaviors such as foraging and resting, there could be long-term declines in vital rates ( Lusseau and Bejder, 2007; Parsons, 2012). If whale-watching vessels are repeatedly perceived as a threat, hormonal responses leading to chronic stress can suppress growth and limit reproduction ( Atkinson et al., 2015). For females, reduction in time spent foraging could compromise energetic budgets required to produce and raise a calf, resulting in population decline ( Bejder et al., 2006a; Parsons, 2012; New et al., 2015). Over time, whales may also alter habitat use and distribution in response to whale-watching vessel presence ( Bejder et al., 2006b; Cartwright et al., 2012).

To mitigate the potential negative consequences of disturbance from whale-watching vessels, guidelines and regulations have been established for commercial whale-watching operations in over 40 countries ( Carlson, 2013). In the United States, all cetaceans are protected under the Marine Mammal Protection Act of 1972 (MMPA), and endangered cetaceans are further protected under the Endangered Species Act of 1973 (ESA). In accordance with the MMPA, the National Oceanic and Atmospheric Administration (NOAA) has established formal whale-watching regulations and voluntary guidelines aimed to protect marine mammals from injury and behavioral disturbance. Each NOAA Fisheries Regional Office has developed marine mammal viewing regulations and guidelines tailored to the specific needs of the region. In U.S. Atlantic and Alaska regions NOAA and the Whale and Dolphin Conservation sponsor Whale SENSE ( NOAA Fisheries Whale and Dolphin Conservation, 2018), a voluntary conservation and stewardship program that recognizes participating commercial whale-watching operators. Participating tour companies complete training, undergo evaluation, and agree to follow regional whale-watching guidelines.

Humpback whales ( Megaptera novaeangliae) exist in every major ocean basin ( Muto et al., 2018) and are a popular focal point of many whale-watching tours ( O'Connor et al., 2009). Southeast Alaska is a productive feeding ground for the Central North Pacific humpback whale stock, designated as "depleted" by the MMPA ( Muto et al., 2018). The ESA further categorizes stocks into Distinct Population Segments (DPS) based on their breeding areas. In Southeast Alaska, 94% of humpback whales belong to the Hawaii DPS ( Calambokidis et al., 2001; Baker et al., 2013; National Oceanic and Atmospheric Administration, 2016) and 6% belong to the Mexico DPS ( Muto et al., 2017). In 2016, the Hawaii DPS was delisted and designated as "not at risk" under the ESA, while the Mexico DPS was listed as "threatened" ( National Oceanic and Atmospheric Administration, 2016). Overall, the humpback whale population in the North Pacific has grown at approximately 7% per year ( Muto et al., 2017) with an estimated 1,585 individuals in Southeast Alaska in 2008 ( Hendrix et al., 2012). Humpback whales migrate to Southeast Alaska from low latitude breeding grounds and are reliably present from May to September ( Lopez and Pearson, 2017). Acquiring nutrients and energy on the Alaskan feeding grounds is essential for body maintenance and preparation for migration to low-latitude breeding grounds where humpback whales fast due to limited prey availability ( Irvine et al., 2017).

Whale watching has become a lucrative industry and an important source of income to many Southeast Alaska coastal communities, with an estimated annual value of $32 million in the city of Juneau alone ( O'Connor et al., 2009). To meet the demand of the rapid growth of tourism in Juneau, the whale-watching industry has tripled since 2000. Currently, there are approximately 65 vessels that offer dedicated whale-watching tours, in addition to fishing charter vessels which view whales opportunistically ( Di Clemente et al., 2018). Due to this surge in vessel presence, it is unclear if the current Alaska whale-watching regulations, established in 2001 ( Table 1), are sufficient to mitigate potential disturbance to humpback whales.

Crowding of whales is of particular concern in the Juneau whale-watching tour area due to complex geography consisting of narrow channels and obstructed waterways ( Weingartner et al., 2009). Compared to other whale-watching locations (e.g., Stellwagen Bank, Hawaiian Islands) characterized by open waters for viewing humpback whales, opportunities for vessel dispersion in Southeast Alaska are limited. All tours in Juneau depart out of a single port, Auke Bay, concentrating all whale-watching vessels in a tour area approximately 30 × 15 km in size ( Teerlink et al., 2018). Throughout the summer, humpback whales vary in number and distribution throughout the region, which influences the number of vessels watching an individual or group at any given time. For example, bubble net feeding groups (i.e., highly conspicuous, and cooperative surface-feeding groups that release underwater bubble streams to corral schools of Pacific herring toward the surface, Sharpe, 2001), can attract as many as 30 vessels ( Teerlink, 2017) at once. Furthermore, the long daylight hours during the Alaskan summer allows whale-watching vessels to operate for extended periods from 7:00 am to 9:00 pm. As a result, whales may be exposed to whale-watching vessels for the majority of the 24-h cycle. The sustainability of the Juneau whale-watching industry will likely have far-reaching and long-term ecological and economic effects throughout Southeast Alaska as some of the same humpback whales travel between Juneau and other popular tourist communities such as Ketchikan, Sitka, Hoonah, Skagway, and Glacier Bay ( Hendrix et al., 2012).

In order to ensure that proper mitigation measures are in place to protect the resource upon which the industry relies, the goal of the present study was to assess the effects of whale-watching vessels on humpback whales in Juneau, Alaska. The objectives were to determine how humpback whale movement and behavioral patterns are affected by (1) vessel presence and the number of vessels present and (2) time spent in the presence of vessels, and to assess the effect of (3) vessel presence on humpback whale behavioral state transitions.

Materials and Methods

Data Collection

Land based observations occurred at Point Lena (58.39140 N, 134.77495 W) and Point Retreat (58.41308 N, 134.95644 W) ( Figure 1). Data were collected using a Sokkia DT-5A theodolite connected to a laptop computer using the data acquisition software, Mysticetus. Data collection required a team of at least 3 people, consisting of a theodolite operator, computer operator, and 1-2 spotters. Humpback whales were observed using a Konus 20 × 60 spotting scope and Leica 10 × 42 binoculars. Behavioral events and states were classified using an ethogram ( Table 2). During each field day, environmental variables, including visibility, cloud cover, precipitation, and Beaufort sea state, were collected every hour or as conditions changed. Due to daily tidal fluctuations of up to 5 m, theodolite station height was measured approximately every 15 min using vertical markers on the shoreline. To ensure reliable data collection, observations were made only in Beaufort sea state of ≤3, little or no rain, and <15 kt wind.

Humpback whale movement and behavioral data with respect to whale-watching vessel presence were collected using theodolite tracking methods described in Würsig et al. (1991) and behavioral observation methods described in Di Clemente et al. (2018). A "sighting" (i.e., observation period of behaviors for a humpback whale) began when an individual was spotted < 5 km from the field site. Focal follow observations with all-occurrence sampling ( Altmann, 1974) was used to record behavioral events ( Table 2) and continuous sampling was used to record behavioral state, heading, and number of vessels present within a 500 m radius of the whale at the time of the behavioral event. A 500 m threshold was used previously by Di Clemente et al. (2018) as an intermediate distance between distance thresholds previously used in whale-watching studies on humpback whales [300 m ( Corkeron, 1995; Morete et al., 2007) and 1000 m ( Gulesserian et al., 2011; Schaffar et al., 2013)]. Vessels were considered present when within 500 m of the whale and observed approaching, departing, or tracking (i.e., following a whale in a straight line or in a parallel line according to the last heading observed of the whale). Simultaneously, the theodolite was used to obtain successive latitude/longitude coordinates of humpback whale positions, which were plotted as polyline tracks on Mysticetus. A "track" of the individual included all positions recorded along with time, distance from field site, and number of vessels within 500 m. Distinct physical markings (e.g., unique coloration, scarring, fluke notching, or dorsal fin shape) were recorded throughout the observation to aid in confirming the focal animal. If a second humpback whale was spotted < 5 km from the theodolite station, sighting and track information were collected on both individuals as long as accuracy was maintained. Groups > 1 whale (e.g., bubble net feeding groups and mother-calf pairs) were not included in the dataset because the focal animal could not be reliably determined throughout the follow. However, this excluded only a small portion of the dataset.

No limit was set for the duration of sightings or tracks. The mean dive time for humpback whales in Southeast Alaska is <10 min ( Dolphin, 1987), therefore a sighting ceased once an individual went undetected for >20 min or had been absent from the study area >10 min. An individual was considered "absent" if it was out of range (i.e., >5 km from the theodolite, verified on Mysticetus) or out of sight due to trees or presence of islands. This distance has been recommended for stations between 20 and 45 m above mean low sea level to reduce errors in precision from targets at greater distances ( Würsig et al., 1991; Piwetz et al., 2018). This method was similarly used by Di Clemente et al. (2018) to minimize the chance of sampling an individual that was different from the original focal animal.

In the summer of 2017, 20 companies advertised whale-watching tours or charters in Juneau, AK (Schuler, unpublished data). The industry included vessels ranging in size from 8 to 32 m and accommodating between 6 and 144 passengers. Each vessel departed from Auke Bay Harbor ( Figure 1), conducting up to 3 tours per day that averaged 2.5-3 h each. In addition to these commercial whale-watching vessels, private vessels would also opportunistically track humpback whales.

Variables

Movement

Movement metrics

Successive positions of a humpback whale were used to obtain deviation, speed, and directionality and used to calculate changes in movement ( Würsig et al., 1991). Deviation is the relative turning angle between three consecutive positions ( Christiansen et al., 2013b). Deviation indicates path predictability for each position in the track by estimating the angle between the path taken and the straight-line path predicted ( Williams et al., 2002; Christiansen et al., 2013b). Deviation ranges between 0° (linear movement) and 180° (erratic movement) ( Christiansen et al., 2013b). Speed (kph) is the distance traveled between two coordinates divided by the time interval between those two coordinates ( Lundquist et al., 2012). Directionality measured the linearity of movement of each surfacing in the track, calculated by dividing the distance between the two end-points of the specific section of the track by the actual distance of the track line of the section ( Christiansen et al., 2013b). Directionality ranged between 0 (circular movement) and 1 (linear movement) ( Christiansen et al., 2013b). Microsoft Excel (2016) was used to calculate deviation, speed, and directionality using data points recorded on Mysticetus.

Behavior

Behavioral metrics

Inter-breath interval (IBI) and respiration rate (RESP) were used to measure behavioral changes. Humpback whale IBIs were estimated as the time elapsed between two consecutive blows ( Christiansen et al., 2013b). A fluke-up dive was typically associated with a longer IBI, therefore "Dive Type" for each interval was identified as "No fluke" or "Fluke-Up." RESP (blows/min) was calculated by dividing the number of blows observed during a sighting by the total duration of the sighting.

Behavioral state transitions

Each behavioral event was categorized into one of four behavioral states ( Table 2): feeding (FED), resting (RES), surface active behavior (SAB), and traveling (TRA). Over the course of a sighting, the behavioral states comprised a whale's behavioral budgets [i.e., the proportion of time an animal spends in different behavioral states ( Christiansen et al., 2013a)]. A change in behavioral state during a sighting was considered a behavioral transition. Each behavioral transition was categorized into 'presence' situations (i.e., observations in which ≥1 vessels were present <500 m of the focal whale) and 'absence' situations (i.e., observations in which no vessel was present <500 m radius of the focal whale).

Statistical Methods

Presence and Number of Whale-Watching Vessels (Obj. 1)

Regression analyses were performed using the open-source software R v.3.4.3 ( R Core Team, 2018). To assess the significance of whale-watching vessels in explaining variations in deviation, speed, and IBI, linear mixed effects models (LMM) were fit by restricted maximum likelihood using the lme function in the R package nlme ( Pinheiro et al., 2018). Covariates considered for the "base model" included behavioral state, location, time of day (indicated as a percentile of daylight hours, where sunrise = 0 and sunset = 1), Julian date, year, and environmental variables (i.e., visibility, Beaufort sea state) as fixed effects. Sighting distance associated with fixes (i.e., individual data records collected in Mysticetus) were included as an explanatory variable for deviation and speed analysis to account for potential vertical angle measurement errors associated with larger distances from shore. Time between fixes was included for deviation and dive type was included for IBI analysis to account for variability in direction changes and breathing intervals associated with longer dive times. Stepwise model selection based on the corrected Akaike Information Criterion (AICc) was used to select the combination of covariates that best explained the variations in each metric. As humpback whales may exhibit individually specific behaviors ( Peterson, 2001), whale ID was included in each model as a random effect (intercept) to account for variability in mean deviation, speed, or IBI among individual whales. Two individuals (IDs 1538 and 1839 from the Alaska catalog) were seen frequently in the study area and could be readily identified based on their distinctive pigmentation on the underside of their flukes and dorsal fin shape. All observations of these identifiable individuals (i.e., 1538 and 1839) were included under the same unique identification numbers.

For each metric, a series of alternative models were used to test the possible effects of whale-watching vessels. The first model included vessel presence (vessels = 0 vs. vessels > 0) as a fixed effect to compare whale movement and behavior when vessels were present to those in which vessels were absent. The second model included the number of vessels as a linear fixed effect to understand how increasing numbers of vessels may influence movement and behavior. The third model included a categorical variable for the number of vessels to examine results for possible non-linearities and threshold effects. For deviation and speed, spatial autocorrelation was accounted for since measurements closer in space were likely to be more similar than those farther apart. For IBI, temporal autocorrelation was accounted for by including a first-order autoregressive term to model the possible dependence between consecutive residuals as ε t = ϕ ∗ε t-₁ + ν t, where ϕ is the first-order auto-regressive coefficient and the errors (innovations ν t) are assumed to follow a Gaussian distribution. Errors (ν t) were examined for normality and homoscedasticity. The AICc was used to select the best-fit model while maintaining model parsimony.

Percent Time With Vessels (Obj. 2)

The percent time spent with vessels (PERC) was calculated by taking the sum of intervals spent in the presence of vessels and dividing it by the total length of the track or sighting. Linear regression was used to test for possible effects of PERC on directionality and RESP, while controlling for overall behavioral state (i.e., traveling, feeding, resting, surface active, and mixed), Julian date, year, location, and duration of track or sighting.

Behavioral State Transitions (Obj. 3)

To examine changes in whale activity budget with respect to whale-watching vessels, first-order Markov chain analyses were used to build transition matrices and run Monte Carlo simulations in situations in which whales were in the presence of vessels and in the absence of vessels (presence vs. absence). A first-order Markov chain was deemed appropriate for accounting for temporal autocorrelation while quantifying the dependence of a succeeding behavioral state ( Lusseau, 2003). Based on the resulting contingency tables, presence and absence transition probability matrices were calculated (for details, see Di Clemente et al., 2018).

Monte Carlo simulations were also used to estimate the activity budgets of whales during vessel presence and absence situations (for details, see Christiansen et al., 2013a; Di Clemente et al., 2018). For presence and absence situations, simulations were repeated 1000 times, each representing a 7.5 h long time series either in the presence or the absence of whale-watching vessels. The resulting distribution was plotted using the relative proportion of each behavioral state in each situation. Initial model runs indicated that RES could not be included in Monte Carlo simulations due to its infrequent occurrence that resulted in a 100% transition probability. RES was therefore not included in the simulations.

Results

Data were collected on 147 days (111 days from Point Lena and 36 days from Point Retreat) from June through October 2016 and May through September 2017, totaling 843 h of effort (621 h from Point Lena, 223 h from Point Retreat) ( Table 3). Only sightings consisting of ≥10 min of observed behaviors were included to ensure adequate IBI sample size. Tracks composed of ≥4 fixes were included to ensure at least two data points were included for deviation analysis. With these considerations, 201 humpback whale sightings and 178 whale tracks were included for analysis, totaling 162 h of behavioral observations ( Table 3). The mean duration of a sighting was 49 ± 47.7 SD min (range = 12 - 447 min). The mean number of fixes in a track was 18 ± 24.3 (range = 4 - 213).

Presence and Number of Vessels (Obj. 1)

Summary statistics for deviation, speed, and IBI were calculated in the presence and absence of vessels ( Table 4). The mean number of vessels observed for each fix was 0.8 ± 1.41 (range = 0 - 8). In the presence of vessels, 59.9% of fixes included more than one vessel ( n = 743). The estimated whale deviation from their straight-line course was 38.9% higher in the presence of vessels than in the absence of vessels based on the AICc-best model ( p < 0.001, Table 5). Using the number of vessels instead of vessel presence in the same model resulted in an estimated increase in deviation by 6.2% per additional vessel ( p = 0.022), but the model had less support (ΔAICc = 14.77). Whale swimming speed was 5.4% faster in the presence vs. absence of vessels ( p = 0.047, Table 6). However, the number of vessels did not have a significant effect on speed. While IBI was 6.7% shorter in the presence vs. absence of vessels ( p = 0.025), AICc model comparisons indicated that a linear effect of the number of vessels on IBI resulted in a better model (ΔAICc = 5.78), suggesting a 3.4% decrease in IBI for each additional vessel ( p = 0.001, Table 7). The categorical model for number of vessels did not indicate an obvious threshold effect for deviation, speed or IBI.

Table 5. Estimated coefficients and standard errors from the AICc-best linear mixed effects model of the effects of vessel presence on log(Deviation) ( n = 2950 fixes) while controlling for behavioral state, location, Julian date, Beaufort sea state, distance from site, and time between fixes.

Table 6. Estimated coefficients and standard errors from the AICc-best linear mixed effects model of the effect of vessel presence on sqrt (Speed) ( n = 3,136 fixes) while controlling for behavioral state, year, location, and distance from site.

Table 7. Estimated coefficients and standard errors from the AICc-best linear mixed effects model of the simple linear effect of number of vessels on log(Inter-Breath Interval) (IBI) ( n = 5,396 observations), while controlling for behavioral state, location, time, Julian date, year, and dive type.

Percent Time Spent With Vessels (Obj. 2)

The mean percent time humpback whales were observed in the presence of vessels was 33% ± 39.2% (range = 1-100%) during tracks and 29% ± 36.7% (range = 1-100%) during sightings. During 40% of tracks and 44% of sightings, no vessels were present. During 16% of tracks and 11% of sightings, vessels were present for the entire time. Humpback whale directionality averaged 0.72 ± 0.308 (range = 0.01-1.00, n = 177) and RESP averaged 0.55 ± 0.26) breaths/min (range = 0.16-1.52, n = 201). Percent time spent in the presence of vessels did not significantly affect directionality. However, the best fit model for RESP included percent time spent with boats, behavioral state, date, and location, and indicated that the more time a whale spent in the presence of vessels during a track, the higher the RESP ( p = 0.011).

Behavioral State Transitions (Obj. 3)

A total of 5,489 behavioral events were recorded during 201 sightings (presence: 40.3%, n = 2213; absence: 59.7%, n = 3,276; Table 8). In the presence and absence of vessels, the predominant behavioral state observed was TRA (presence: 66.6%, absence: 76.1%), followed by FED (presence: 31.7%, absence: 21.5%), RES (presence: 1.4%, absence: 1.6%), and SAB (presence: 0.3%, absence: 0.8%). Markov chain analysis including TRA, FED, and SAB indicated that the transition probability between behavioral states differed by vessel presence (goodness-of-fit test, χ ² = 33.4; df = 4; p < 0.001). In the presence and absence of vessels, whales were likely to continue engaging in FED and TRA (FED → FED, presence = 96.7%, absence = 95.7%; TRA → TRA, presence = 98.2%, absence = 98.5%). In the presence of vessels, SAB more frequently transitioned to FED (SAB → FED, presence = 42.9%, absence = 3.7%) or TRA (SAB → TRA, presence = 14.3%, absence = 7.4%), while in the absence of vessels, whales were more likely to continue SAB (SAB → SAB, absence = 88.9%, presence = 42.9%).

Monte Carlo simulations indicated that in the presence of vessels, the activity budgets of whales included less TRA and SAB ( Figure 2). In the presence of whale-watching vessels, TRA composed 71.1% of the activity budget, compared to 80.7% in the absence of vessels, and SAB was 0.2% in the presence of vessels, compared to 0.9% in the absence of vessels. FED was also a large proportion of the activity budgets of whales, consisting of 28.6% in the presence of vessels and 18.4% in the absence ( Table 9).

Discussion

The results of this study reveal differences in humpback whale movement and behavior according to the presence of vessels, number of vessels, and time spent with vessels. Overall, in the presence of vessels, humpback whales demonstrated a larger deviation from their straight-line path, higher swimming speeds, and shorter IBIs. Higher deviation and shorter IBIs were also associated with the number of vessels, deviation significantly increasing and IBI significantly decreasing with each additional vessel present. A higher percentage of time spent with vessels was also correlated with higher RESP. Humpback whales that were feeding or traveling were likely to continue in those behavioral states whether in the presence or absence of vessels, but individuals were more likely to cease surface activity in the presence of vessels.

Whale-Watching Vessels (Obj. 1)

Horizontal movement metrics, such as changes in direction and increased swimming speed, are often used to identify vessel avoidance strategies by whales ( Baker and Herman, 1989; Schaffar et al., 2013; Christiansen et al., 2014). The present study detected both a 38.5% higher deviation and 5% higher speed in the presence of vessels. Humpback whales have previously demonstrated increased path sinuosity ( Schaffar et al., 2009; Stamation et al., 2010) and avoidance orientation in relation to vessels ( Baker and Herman, 1989). Increased speeds in the presence of vessels has also been detected on humpback whale breeding grounds in the South Pacific ( Schaffar et al., 2013) and South Atlantic ( Morete et al., 2007). Direction changes and increased speeds are an energetically efficient strategy for humpback whales to avoid a perceived threat ( Ford and Reeves, 2008; Senigaglia et al., 2016). While this 'flight' response may require less energy than a 'fight' response (i.e., surface-active behaviors) ( Pitman et al., 2017), increased energetic expenditure spent avoiding vessels in highly trafficked areas, like Juneau, could be cumulative and decrease physical fitness over time.

Indicators of disturbance include changes in dive patterns and surfacing intervals ( Bejder and Samuels, 2003). In the present study, shorter IBI in the presence of vessels indicates an increase in blow frequency. Furthermore, as the number of vessels increased, humpback whales exhibited significantly shorter IBI. These results support a meta-analysis by Senigaglia et al. (2016), which determined that mysticetes (i.e., baleen whales) tended to decrease IBI when whale-watching vessels were present. Previous studies in Juneau have also associated the presence of vessels with changes in breathing intervals ( Baker et al., 1986) and increased variability in time spent at the surface ( Peterson, 2001). Similarly, fin whales ( Balaenoptera physalus) off the coast of Maine exhibited higher respiration rates and reduced dive durations, surface durations, and number of blows per surfacing sequence when whale-watching vessels were nearby ( Stone et al., 1992). A decrease in IBI during interactions with whale-watching vessels can be of particular concern when it indicates a relative decrease in foraging efficiency, as seen in minke ( B. acutorostrata) and fin whales ( Christiansen et al., 2013b; Lesage et al., 2017). Furthermore, shorter IBI in the presence of vessels can reflect increased energetic expenditure and result in higher levels of oxygen consumption needed to recover (e.g., from increased speed to avoid vessels) ( Christiansen et al., 2014).

Time Spent With Vessels (Obj. 2)

As the percent time spent with vessels increased, the respiration rate increased. Over the course of a track, whales may be disturbed by vessel noise of tracking whale-watching vessels ( Richardson et al., 1995) due to the strong or rapid changes in engine and propeller speed ( Watkins, 1986). Alterations in whale breathing patterns to persistent vessel exposure can indicate vessel avoidance of these sound levels. Multiple vessels simultaneously tracking a whale will accentuate this effect ( Holt et al., 2009). Vessel characteristics (e.g., size and engine type) and vessel approach (e.g., angle and speed) are also likely to elicit different responses in whales. However, these factors could not be isolated due to the large proportion of humpback whale observations collected in the presence of >1 vessel. Furthermore, while the present study considered vessels present as those tracking whales within 500 m, it is likely that the vessel detection range for whales is >500 m ( Baker and Herman, 1989; Richardson et al., 1995) as cetaceans respond to stimuli as far as tens of kilometers away ( Baker and Herman, 1989; Richardson et al., 1995). Therefore, disturbance from vessel noise may be heightened in heavily trafficked areas, like Juneau. While not measured in the current study, information regarding detectable ranges of vessel engine sound in the tour area, and observations of whale movement and behavior with larger vessel distance thresholds, would help to validate this supposition.

Behavioral State Transitions (Obj. 3)

The present study reflects results from data collected in Juneau by Di Clemente et al. (2018), which demonstrated that humpback whale activity budgets in the presence of vessels consisted of less traveling and more feeding than in the absence of vessels. This could also reflect that whale-watching tours are more likely to select a feeding whale to watch over a traveling whale. However, humpback whales did not alter their feeding or traveling behaviors based on vessel presence. Previous research in Alaska has indicated that feeding humpback whales are less likely to alter their behavioral state in response to approaching vessels than non-feeding whales ( Krieger and Wing, 1984, 1986; Peterson, 2001), suggesting that the need to build energy reserves while on the feeding grounds supersedes abandoning feeding even if disturbed. Responses may also occur beneath the surface, such as decreases in humpback whales feeding efficiency as seen with increased sound levels from vessels ( Blair et al., 2016). By contrast, minke whales in Faxafloìi Bay, Iceland, decreased feeding behavior as a result of whale-watching vessel presence ( Christiansen et al., 2013b). Differences in observed responses may vary by prey type, prey densities, and availability of food elsewhere ( Krieger and Wing, 1986). Furthermore, the low number of recorded transitions between traveling and feeding could reflect the inability of shore-based observations to confirm humpback whales feeding at depth. Due to the importance of feeding in the area, it is possible that some straight, directional movement observed at the surface, could have also included feeding beneath the surface.

The only significant effect of vessel presence on humpback whale activity budgets was with respect to surface active behavior. Similar to Di Clemente et al. (2018), humpback whales in the absence of vessels were more than twice as likely to continue surface active behaviors, and whales in the presence of vessels were twice as likely to transition from surface active behavior to traveling. In other studies in Alaska, humpback whales increased surface active behaviors in the presence of vessels, potentially representing aggressive (e.g., tail breaching and lob tailing) and negative responses to vessels ( Baker and Herman, 1989; Peterson, 2001). Transitions from vocal communication to non-vocal surface-generated communication (i.e., breaching, tail-slapping) by humpback whales have also been detected in noisy environments (i.e., increased background noise, high wind speeds) ( Dunlop et al., 2010). However, surface active behavior has also been attributed to communication to distant groups ( Kavanagh et al., 2017). This indicates that cessation of surface active behavior could result from acoustic masking due to vessel noise and subsequent inability to communicate ( Richardson et al., 1995; Gabriele et al., 2018). However, due to the relatively small proportion of time whales spend resting and in surface active behaviors, in comparison to feeding and traveling, a larger sample size is needed to support the findings of the present study.

Potential Long-Term Effects

The present study did not directly address long-term consequences of vessel presence; however, it is possible that the measured short-term effects on whale movement and behavior could have cumulative effects on individuals and local populations in areas of high disturbance. Increased energetic expenditure and potential decreases in feeding efficiency, as evidenced by increased direction changes, higher traveling speeds, and changes in breathing and diving patterns, could have negative long-term effects. Prolonged energetic expenditure due to vessel avoidance behaviors may deplete energy reserves and disrupt homeostasis, ultimately causing physical fitness decline in whales ( Beale, 2007). These physiological consequences, if extreme enough, could cause population decline, influencing reproductive success or decreasing chances of survival ( Bejder and Samuels, 2003).

Humpback whales exhibit a high degree of feeding site fidelity ( Calambokidis et al., 2001; Weinrich and Corbelli, 2009) to both general feeding areas ( Baker et al., 1990) and to specific regions within the feeding grounds ( Weinrich, 1998; Stevick et al., 2006). This may be an adaptive strategy to maximize prey intake by feeding on "known" prey resources that are predictable in time and space ( Stevick et al., 2006). Humpback whales that remain in highly trafficked areas despite high exposure to vessel presence and associated stressors may do so because they rely on the resources from that area or they no longer perceive the presence of vessels as a threat.

Negative effects on whales may be minimized over time by habituation to vessel presence ( Watkins, 1986). On the New England feeding grounds, Watkins (1986) determined that since whale watching began in 1976, humpback whales in the presence of vessels are more likely to continue their previous activity or respond by approaching vessels. Furthermore, despite high vessel pressure in the Juneau tour area, several individual humpback whales continue to return in subsequent years, often being observed multiple times a season ( Teerlink, 2017). In a study by Teerlink et al. (2018), humpback whales in the Juneau area at the end of a whale-watching season (September) did not exhibit higher levels of the stress hormone, cortisol, compared to more remote regions. The lack of physiological stress responses detected in humpback whales in Juneau could indicate that repeated short-term disturbances may not be causing chronic stress. However, it is also possible that whales more sensitive to the presence of vessels had already left the tour area to avoid vessels, and the samples of whales in Juneau were biased toward whales more tolerant of vessels ( Bejder et al., 2006a).

The expansion and persistence of vessel presence could result in alteration of humpback whale ranging patterns or habitat utilization. Changes in humpback whale distribution in an effort to avoid vessels could be detrimental not only to the whales, but to the profitability of the Juneau tour industry. In nearby Glacier Bay, habitat abandonment by humpback whales in response to vessel exposure has already been documented ( Dean et al., 1985). Similarly, individual humpback whale singers in Brazil have responded to high vessel traffic by either moving out of recording range or discontinuing songs ( Sousa-Lima and Clark, 2008). Bottlenose dolphins in Milford Sound, New Zealand have also adjusted their seasonal residency patterns in response to heavy vessel traffic ( Lusseau, 2005).

Management Recommendations

Regulations were established in Alaska to prevent "take," defined under the MMPA as an action to "harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal." The present study revealed that there are significant differences in short-term whale movement and behavioral patterns in the presence of vessels. This indicates that the current regulations, including to "not disrupt the normal behavior or prior activity of a whale" ( Table 1), may not be adequate to reduce takes of humpback whales. Therefore, revisiting the humpback whale approach regulation and expanding the existing vessel approach limit to create a larger buffer around the whales should be considered by management to help reduce vessel impacts on humpback whales. The present study also determined that changes in deviation and IBI occurred in response to the number of vessels. Restrictions on the maximum number of vessels around whales or limits to the number of vessels in the industry does not currently exist. Managing the number of vessels watching whales would minimize vessel effects on whale movements and behavior.

The management approach in Alaska should continue to be supplemented with education programs encouraging operator participation in voluntary best practices. Whale SENSE was introduced in Alaska in 2015 ( NOAA Fisheries Whale and Dolphin Conservation, 2018). In 2018, 44% of the companies that offered dedicated whale-watching tours in Juneau participated in the program, consisting of approximately 67% of vessels in the industry (Schuler, unpublished data). This program aims to minimize harassment of whales through the education of naturalists, captains, and passengers and promotion of responsible whale-watching practices. Programs such as Whale SENSE can help to manage tourist viewing expectations and encourage operator compliance ( Filby et al., 2015). By combining evidenced-based regulations with effective educational programs, a sustainable whale-watching industry can be maintained.

Conclusion

The whale-watching industry in Juneau, Alaska, has grown alongside increasing humpback whale populations and rising tourist demand over the past 20 years. The present study revealed significant short-term differences in humpback whale movement and behavior in the presence of vessels that could negatively impact the health and predictability of the resource on which the industry relies. To determine if the short-term behavioral effects observed in this study manifest into long-term fitness consequences, the population should continue to be monitored. In the meantime, it is recommended that management bodies revisit the current regulations and guidelines and incorporate recent scientific research findings to ensure the sustainability of the industry. The precautionary principle, which should provide a buffer for scientific uncertainty ( Reynolds et al., 2009), and proactive approaches should be implemented in order to ensure the viability of the whale-watching industry and the species upon which it depends.

Data Availability Statement

The datasets generated for this study are available on request to the corresponding author.

Author Contributions

AS collected and analyzed the data and wrote the manuscript. SP provided guidance on study design and data analysis, and wrote the manuscript. JD helped with study design, and data analysis, and wrote the manuscript. DS provided guidance on study design and data analysis, and reviewed the manuscript. FM helped with data analysis and wrote the manuscript. HP conceived the study, obtained funding, provided guidance on study design and data analysis, and wrote the manuscript.

Funding

This research was sponsored by Alaska Sea Grant, University of Alaska Fairbanks (project # R/112-05), with funds from the National Oceanic and Atmospheric Administration (Grant NA14OAR4170079), and from the University of Alaska with funds appropriated by the state of Alaska. Additional funds were provided by Alaska EPSCoR NSF (Grant Number OIA-1208927) and the NOAA Ernest F. Hollings Undergraduate Scholarship Program.

Conflict of Interest

DS was employed by company Mysticetus LLC.

The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The reviewer BW declared a shared affiliation, with no collaboration, with several of the authors, AS, FM, and HP to the handling Editor at the time of review.

Acknowledgments

This project would not have been possible without data collection assistance by Chase Ammon, Madison Bargas, Taelor Brandon, Cody Crumpton, Dana Flerchinger, Holly Kelchner, Anneliese Moll, Breanna O'Farrell, Lindsey Overcast, Robert Schuler, and Margaret Sherman. Logistical support at the National Oceanic and Atmospheric Administration Ted Steven's Marine Research Institute was provided by John Moran and Gordon Garcia, and access to the Point Retreat Lighthouse field site was generously provided by Dave Benton and Lori Tefler of the Alaska Lighthouse Association.

Footnotes

References

NOAA Fisheries Whale and Dolphin Conservation, (2018). Whale SENSE: Promoting Responsible Whale Watching. Available at: www.whalesense.org (accessed November 1, 2018).
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# data[].attributes.attachment_link.title
Humpback Whale Movements and Behavior in Response to Whale-Watching Vessels in Juneau, AK

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The whale-watching industry in Juneau, Alaska relies primarily on the presence of North Pacific humpback whales (Megaptera novaeangliae). To meet demands from the rapidly growing tourism industry, the number of whale-watching vessels in this region has tripled over the last 18 years.

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Humpback whales are one of the most-watched and well-studied species of whale. Found in every ocean and many nearshore areas associated with coastal and marine tourism, they are the focus of whale watching operations in over many countries around the world. The species is known for its spectacular "surface active behaviour", which can include breaching (leaping clear of the water) and flipper and tail slapping, its occasional curiosity around tour boats, and its complex 'song', which is heard on the breeding grounds in the tropics. A humpback whale's blow or the splash of a breach can be seen from a distance of several kilometres, making the humpback one of the more conspicuous targets of whale watching around the world. At close range, the species is unlikely to be confused with any other, due to the distinctive characteristics detailed below:

Distribution

Humpback whales occur worldwide in all major oceans. While they generally demonstrate a preference for continental shelf areas, they are also known to cross deep offshore waters, and spend time over and around seamounts in the open ocean.

Native to the following countries**: Angola; Anguilla; Antigua and Barbuda; Argentina; Aruba; Australia; Bahamas; Bangladesh; Barbados; Benin; Bermuda; Bonaire, Sint Eustatius and Saba (Saba, Sint Eustatius); Brazil; Cameroon; Canada; Cape Verde; Cayman Islands; Chile; Cocos (Keeling) Islands; Colombia; Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica; Côte d'Ivoire; Cuba; Curaçao; Denmark; Djibouti; Dominica; Dominican Republic; Ecuador; El Salvador; Equatorial Guinea; Falkland Islands (Malvinas); Faroe Islands; Fiji; France; French Polynesia; French Southern Territories; Gabon; Gambia; Ghana; Greenland; Grenada; Guadeloupe; Guam; Guatemala; Haiti; Honduras; Iceland; India; Indonesia; Iran, Islamic Republic of; Ireland; Jamaica; Japan; Kenya; Kiribati; Korea, Democratic People's Republic of; Korea, Republic of; Madagascar; Malaysia; Maldives; Marshall Islands; Martinique; Mauritania; Mauritius; Mexico; Morocco; Mozambique; Myanmar; Namibia; Nauru; New Caledonia; New Zealand; Nicaragua; Nigeria; Niue; Northern Mariana Islands; Norway; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Pitcairn; Portugal; Puerto Rico; Réunion; Russian Federation; Saint Helena, Ascension and Tristan da Cunha (Tristan da Cunha); Saint Kitts and Nevis; Saint Lucia; Saint Martin (French part); Saint Pierre and Miquelon; Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Senegal; Seychelles; Sint Maarten (Dutch part); Solomon Islands; Somalia; South Africa; South Georgia and the South Sandwich Islands; Spain; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Timor-Leste; Togo; Tonga; Trinidad and Tobago; Tunisia; Turks and Caicos Islands; Tuvalu; United Arab Emirates; United Kingdom; United States; Uruguay; Vanuatu; Venezuela, Bolivarian Republic of; Vietnam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara; Yemen

** Note: as many populations of humpback whales increase in number following the moratorium on whaling, the species appears to be expanding its range, and is observed more frequently in areas where it was previously thought to be only vagrant, including off the coast of the Netherlands, in various parts of the Red Sea, and the Mediterranean.

Migration

Every known population of humpback whales, with the exception of the Endangered Arabian Sea population, performs long seasonal migrations; spending summers feeding in cold productive waters at high latitudes and winters on tropical breeding grounds where they mate, calve, and nurse their young. Some individuals travel as far as 8,000km between their breeding and feeding grounds. Southern Hemisphere populations generally feed around the Antarctic between November and March, and migrate toward breeding grounds near the equator where they mate and give birth between July and October. Northern Hemisphere populations do the opposite, feeding at high latitudes off the continents of North America and Europe between June and October, and mating and calving at low latitudes in the Caribbean, West Pacific and West Atlantic between December and March or April (see map below).

Biology and Ecology

Feeding

Humpback whales in the Southern Hemisphere feed primarily on krill, small shrimp-like crustaceans that are highly abundant in the waters around Antarctica. Populations in the Northern Hemisphere feed on a variety of prey, including many different species of small shoaling fishes, such as anchovies, herring, sand lance, and sardines. Humpback whales use a range of feeding strategies, including lunge feeding and bubble netting, a process in which whales either singly or cooperatively blow a circle of bubbles from under water in order to create a wall or curtain of bubbles that traps small schooling fish and makes them easier to capture in a single lunging gulp through the centre of the bubble curtain. Humpback whales need to feed intensively throughout the summer and autumn, as they generally fast during migration and on the breeding grounds and rely on fat reserves for energy during those months. However, there is mounting evidence that at least some individuals engage in opportunistic feeding during migration or at lower latitudes associated with breeding habitat. There is also evidence that at least some individuals from some populations forego migration altogether in some years and remain on feeding grounds throughout the winter months. Shifts in ocean productivity, probably a result of climate change, have almost certainly played a role in some of the recently observed changes or anomalies in migration patterns and feeding grounds. The non-migratory population of humpback whales in the Arabian Sea, probably split from other humpback whale populations in the Indian Ocean roughly 70,000 years ago , process most likely facilitated by the seasonal upwelling of cold, nutrient rich waters, creating feeding opportunities in the same areas that are suitable for mating, calving, and nursing.

Reproduction

Humpback whales mate primarily on their breeding grounds in the tropics in the "wi nter months" (July-October in the Southern Hemisphere and December-March in the Northern Hemisphere). A pregnant female swims thousands of kilometers to nutrient-rich temperate or polar feeding grounds to gain sufficient strength and body mass for successful birth and lactation by feeding intensively for several months. Pregnant females usually arrive earlier than males, non-pregnant females and juveniles. Then she returns to the breeding ground to give birth after a gestation period of approximately 11.5 months. Mothers and calves generally remain in shallow, sheltered waters where the calf nurses and gains the weight and strength required to migrate back to the feeding grounds. Males on the breeding ground engage in aggressive competitive behaviours to gain access to females, and also produce long complex songs, with all males in the population singing roughly the same song, but slowly changing it over the course of a breeding season.

Research, threats and conservation

Research

Much of what we know about humpback whales today has been learned through photo-identification studies, in which individual whales are photographed and recognized over time by the unique serrations and patterns on the trailing edges and undersides of their tail flukes. In well-studied populations, such as the feeding grounds in Alaska and the Gulf of Maine, some individual whales have been monitored for over 40 years. Technologies like genetic sampling and satellite telemetry (the attachment of small devices that send the whales' GPS position to satellite receivers) allow researchers to track whales' movements and gain more insight into their (seasonal) migrations and fine-scale use of habitat on the breeding grounds and feeding grounds. More information about research techniques used to study whales and dolphins can be found here.

Threats

Natural Predators: Humpback whales often bear rake-like scars on their bodies indicating that they survived an attack by killer whales. Some researchers have proposed that the threat of killer whale attacks, particularly on vulnerable calves, has an important influence on humpback whale behaviour and migration. Large sharks are also potential predators of this species, especially of very young calves.

Human-induced threats: Humpback whales may be at risk from a number of threats, including entanglement in fishing gear, ship strikes, habitat degradation, oil and gas development and climate change. The significance of the impacts of these threats vary across populations. Those populations that are small or that have a restricted range, such as the endangered Arabian Sea population, are of particular concern.

Conservation status

Many populations of humpback whales were heavily hunted through the 1960's, when Soviet whaling operations were still catching humpback whales in the Southern Oceans, the Pacific and the Arabian Sea despite an IWC agreement to stop hunting this species from 1963 onward. The majority of humpback whale populations are recovering well - for example, the recent IWC assessment of Southern Hemisphere humpback whales estimated that overall numbers were at around 70% of the number of whales thought to be in the Southern Hemisphere before hunting began. Globally the species was moved from a status of Vulnerable to Least Concern by the IUCN Redlist of Threatened Species. However, it is under Appendix 1 of the Convention on Migratory Species (CMS), and certain (sub)populations, such as that in the Arabian Sea, are considered endangered by, IUCN, the United States Endangered Species Act ( ESA), and the IWC.

Humpback whales are still hunted in very small numbers under aboriginal subsistence whaling permits and conservative and sustainable quotas are set by the IWC in Greenland and St. Vincent and the Grenadines. There may also be some small-scale hunting of humpback whales around the island of Pagalu in the Gulf of Guinea, but no recent information is available.

Humpback whales and whale watching

Please see the IWC Whalewatching Handbook

References

Show / Hide References

1. Clapham, P. J. in Cetacean Societies (eds J. Mann, R.C. Connor, P.L. Tyack, & H. Whitehead) 173-196 (University of Chicago Press, 2000).

2. Clapham, P. in Encyclopedia of Marine Mammals (eds W. Perrin, B. Wursig, & J.G.M. Thewissen) 582-584 (Elsevier, 2009).

3. Notarbartolo di Sciara, G., Kerem, D. & Smeenk, C. Cetaceans of the Red Sea. CMS Technical series (In press).

4. Minton, G. et al. Megaptera novaeangliae, Arabian Sea subpopulation. IUCN Red List of Threatened Species http://www.iucnredlist.org/det... (2008).

5. Allen, J. M., Rosenbaum, H. C., Katona, S. K., Clapham, P. J. & Mattila, D. K. Regional and sexual differences in fluke pigmentation of humpback whales (Megaptera novaeangliae) from the North Atlantic Ocean. Canadian Journal of Zoology 72, 274-279 (1994).

6. Murase, H., Matsuoka, K., Ichii, T. & Nishiwaki, S. Relationship between the distribution of euphausiids and baleen whales in the Antarctic (35§E - 145§W). 135-145 (2002).

7. Fleming, A. H., Clark, C. T., Calambokidis, J. & Barlow, J. Humpback whale diets respond to variance in ocean climate and ecosystem conditions in the California Current. Global Change Biology, n/a-n/a, doi:10.1111/gcb.13171 (2015).

8. Hain, J. H., Carter, G. R., Kraus, S. D., Mayo, S. A. & Winn, H. E. Feeding behaviour of the humpback whale, Megaptera novaeangliae, in the western north Atlantic. Fishery Bulletin 80, 259-268 (1982).

9. Jurasz, C. M. & Jurasz, V. P. Feeding modes of the humpback whale, Megaptera novaeangliae, in Southeast Alaska. 31, 69-83 (1979).

10. Barendse, J. et al. Migration redefined? Seasonality, movements and group composition of humpback whales Megaptera novaeangliae off the west coast of South Africa. African Journal of Marine Science 32, 1-22 (2010).

11. Thomas, P. O., Reeves, R. R. & Brownell, R. L. Status of the world's baleen whales. Marine Mammal Science, doi:10.1111/mms.12281 (2015).

12. Craig, A., Herman, L. M., Pack, A. A. & Waterman, J. O. Habitat segregation by female humpback whales in Hawaiian waters: avoidance of males? Behaviour 151, doi:10.1163/1568539x-00003151 (2014).

13. Tyack, P. & Whitehead, H. Male competition in large groups of wintering humpback whales. Behaviour 83, 132-154 (1983).

14. Corkeron, P. J. & Connor, R. C. Why do baleen whales migrate? Marine Mammal Science 15, 1228-1245 (1999).

15. Mehta, A. V. How important are baleen whales as prey for killer whales (Orcinus orca) in high-latitude waters? , Boston University, (2004).

16. Clapham, P. J. & Mead, J. G. Megaptera novaeangliae. Mammalian Species 604, 1-9 (1999).

17. Clapham, P. J. et al. Catches of Humpback Whales, Megaptera novaeangliae, by the Soviet Union and Other Nations in the Southern Ocean, 1947-1973. Marine Fisheries Review 71 (2009).

18. Doroshenko, N. V. Soviet catches of humpback whales (Megaptera novaeangliae) in the north Pacific Soviet Whaling Data (1949 - 1979), 48-95 (2000).

19. Mikhalev, Y. A. Humpback whales Megaptera novaeangliae in the Arabian Sea. Marine Ecology Progress Series 149, 13-21 (1997).

20. Reilly, S. et al. Megaptera novaeangliae. The IUCN Red List of Threatened Species http://www.iucnredlist.org/det... (2008).

21. NOAA. (eds National Oceanic and National Marine Fisheries Service (NMFS) & Commerce. Atmospheric Administration (NOAA)) 247 (Department of Commerce, Washington DC, USA, 2016).

22. IWC. Report of the Scientific Committee of the International Whaling Commission 2016: Annex H: Report of the Sub-Committee on Other Southern Hemisphere Whale Stocks. 44 (International Whaling Commission, Bled, Slovenia, 2016).

23. Andriolo, A., Kinas, P., Engel, M., Martins, C. & Rufino, A. Humpback whales within the Brazilian breeding ground: distribution and population size estimate. Endangered Species Research 11, 233-243 (2010).

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Humpback whales are one of the most-watched and well-studied species of whale. Found in every ocean and many nearshore areas associated with coastal and marine tourism, they are the focus of whale watching operations in over many countries around the world.

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Humpback whales are endangered

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Most populations of humpback whales no longer need endangered species protections, according to a decision by the National Marine Fisheries Service.

The U.S. government listed all humpback whales as endangered back in 1970, after commercial whaling had drastically reduced their numbers.

But now, officials say they have divided humpback whales into 14 distinct populations. And after a scientific review, they say that nine of those populations have recovered enough that they no longer need to be considered endangered.

"We believe that we have conducted a very thorough scientific assessment," says Angela Somma, chief of the endangered species division at the agency, also known as NOAA Fisheries. "Most of the humpback populations have increased and increased substantially from where they were."

Whales that are still considered endangered include populations in Central America, off northwest Africa, in the Arabian Sea and in the western north Pacific. And a population near Mexico is listed as threatened. Whales from the Central America and Mexico populations travel through U.S. waters at certain times of year as they feed in areas off the West Coast and Alaska.

As a practical matter, little will change for the whales - they'll still be covered under the Marine Mammal Protection Act, she notes. And the International Whaling Commission's moratorium on hunting these huge ocean creatures, which was imposed in 1982, remains in effect.

"Many of the day-to-day protections and activities will continue to occur," Somma says.

For example, officials have filed regulations to ensure that vessels around Hawaii and Alaska continue to maintain a safe distance from the whales.

Collisions with ships are a danger to the whales, and they face other threats, such as getting tangled up in fishing gear. The Center for Biological Diversity, a conservation group, said nearly 40 reports of whales becoming entangled were recorded off the West Coast in the first half of this year.

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Most Humpback Whales Taken Off Endangered Species List

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Most populations of humpback whales no longer need endangered species protections, according to a decision by the National Marine Fisheries Service. The U.S. government listed all humpback whales as endangered back in 1970, after commercial whaling had drastically reduced their numbers. But now, officials say they have divided humpback whales into 14 distinct populations.

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Ecosystem Roles

Killer whales are top predators in most marine ecosystems and impact the populations of common prey, such as seals and sea lions in breeding areas. Killer whales are host to some endoparasites and ectoparasites. They are host to killer whale lice (Cyamus orcini), trematodes (Fasciola skiranini), cestodes (Trigonocotyle spasskyi), and nematodes (Anasakis simplex).

A disease that affects killer whales and is often studied is toxoplasmosis (Toxoplasma gondii). While this parasite is often benign, it can have serious and fatal effects. (Chadwick, 2001; Murata, et al., 2004; Estes, et al., 1998; Heyning and Dahlheim, 1988; Mann, et al., 2000)

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Humpback Whales Have Made a Remarkable Recovery, Giving Us Hope for the Planet

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Thanks to global cooperation the Humpback whale population is recovering. This gives us an important model for how to heal the oceans.

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The Humpback Whale Studies Program is the longest continuous research program at CCS. It is also one of the most detailed and long-term studies of a baleen whale population. The overarching goal of our work is to advance understanding of humpback whale biology, population status and human impacts. We maintain scientific collaborations with researchers and their institutions worldwide. The program also provides information and data to state, federal and international managers of this species.

The cornerstone of our research is the Gulf of Maine humpback whale population, which has been under continuous study since the 1970s. CCS is the only institution to routinely monitor this population across its feeding range in both U.S. and Canadian waters.

Our Gulf of Maine Humpback Whale Catalog is a synthesis of more than three decades of research on unique individuals. It combines detailed data on life history, behavior, spatial distribution, human impacts and laboratory studies such as molecular genetics. The catalog is the foundation of our Gulf of Maine research and is meticulously curated and updated to maintain its unique scientific value. New techniques for determining pregnancy, health, age and relatedness in large whales are also being developed and ground-truthed with these data.

Outside of the Gulf of Maine, the Center has undertaken extensive research in the West Indies, where humpback whales from all North Atlantic feeding grounds mate and calve. CCS scientists also played important roles in the international YONAH project that studied humpback whales across their known North Atlantic range. Together with a recent follow-up project (MONAH), YONAH has contributed to the understanding of the recovery status of this species in the North Atlantic.

The Center undertakes collaborative research on humpback whale populations in the North and South Pacific. In the North Pacific, we are presently completing an ocean-scale analysis of humpback whale entanglement rates as part of the SPLASH project. In the South Pacific, CCS studies humpback whales at American Samoa, the only U.S. population of humpback whales in the Southern Hemisphere. Through collaboration, this work is providing new insight into the structure and status of humpback whale populations in Oceania.

Learn more about our research through our scientific publications.

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The Humpback Whale Studies Program is the longest continuous research program at CCS. It is also one of the most detailed and long-term studies of a baleen whale population. The overarching goal of our work is to advance understanding of humpback whale biology, population status and human impacts.

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Humpback Whale - Endangered Species Coalition

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These amazing whales migrate throughout the oceans, sing complex vocalizations and use nets of bubbles to capture schools of fish. The humpback whale populations were decimated by whaling and they are currently listed as endangered. The humpback whale (Megaptera novaeangliae)...

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For centuries, humpback whales were hunted to the brink of extinction. But now, following a forty-year initiative to protect them from whalers, their population is finally on the rebound.

In an announcement earlier this week, NOAA Fisheries reported that 9 out of fourteen known populations of humpbacks worldwide have recovered to the point where they no longer qualify to be on the U.S. List of Endangered and Threatened Wildlife. Humpbacks native to the southern hemisphere, in particular, seem to be flourishing.

Five humpback populations are still struggling however, and will retain their current statuses. Four of these are considered endangered, while one population is designated as threatened.

"The data behind the humpback delisting is solid," says Robert Pitman, a NOAA marine ecologist and National Geographic Society grant recipient.

"Those of us that have been on the water working with whales for the past thirty to forty years have been amazed at the recovery that we have seen."

A Species Divided

It may seem unusual to delist part of a species while some populations still remain in dire straits. But according to Marta Nammack, NOAA Fisheries' national Endangered Species Act listing coordinator, doing so makes sense biologically.

While current estimates put the global population at just under 100,000 humpbacks, each of the fourteen populations now recognized by NOAA Fisheries is thought to be genetically distinct. And while some populations do share feeding areas, they each go somewhere different for the breeding season. This means that there doesn't appear to be very much genetic mixing between the populations.

In other words, each population is more or less on its own. And this means we need to assess their perils individually.

For instance, death by entanglement in fishing nets may not pose much of an extinction threat for the humpbacks of Hawaii, says Nammack, because there more than 10,000 whales in that population. But the outlook is altogether different in the Arabian Sea where only 82 humpbacks remain. For this population, every individual death borders on the catastrophic.

"We may not be able to delist the entire species," says Nammack, "but by dividing them up the way we did, we can see substantial progress for their recovery across a good portion of the species."

This would also not be the first time a species was delisted piecemeal. The Eastern North Pacific population of gray whales was taken off the Endangered Species List in 1994 due to successful recovery, but the Western North Pacific population is still considered endangered.

Ongoing Threats

Even though most populations will now be removed from the Endangered Species List, every humpback will still enjoy an array of protections to ensure that their numbers do not plummet once again.

The cetaceans will still be protected under the Marine Mammal Protection Act, which makes it illegal to harass, feed, hunt, capture, collect, or kill any marine mammal within the waters of the United States. Likewise, the International Whaling Commission has had a humpback ban in place since 1982, and Nammack says she doesn't foresee that changing anytime soon.

At the time of the delisting, NOAA Fisheries also stated that it had filed two regulations that maintain 100-yard distance limits that keep whale watching boats and other vessels from getting too close to humpbacks.

"The decision [to delist] shows the power of the Endangered Species Act" says Kristen Monsell, a staff attorney at the Center for Biological Diversity. "But the job isn't done."

Monsell points to threats like climate change, ocean noise, and ship strikes as evidence that humpbacks still need to be protected. "We're lucky to share our oceans with these amazing animals, and we should be doing everything we can to protect them," she says.

Overall, Nammack and Pitman say the delisting is excellent news not just for humpbacks, but also for the programs and legislation that have enabled their recovery.

"This is a win for humpbacks and the listing process," says Pitman. "Delisting is ultimately what we are all after."
Follow Jason Bittel on  Twitter  and  Facebook.

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The Plan to Save the Humpback Whales-and How It Succeeded

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For centuries, humpback whales were hunted to the brink of extinction. But now, following a forty-year initiative to protect them from whalers, their population is finally on the rebound. In an announcement earlier this week, NOAA Fisheries reported that 9 out of fourteen known populations of humpbacks worldwide have recovered to the point where they no longer qualify to be on the U.S.

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The humpback whale ( Megaptera novaeangliae) is a species of baleen whale. It is one of the larger rorqual species, with adults ranging in length from 12-16 m (39-52 ft) and weighing around 25-30 t (28-33 short tons). The humpback has a distinctive body shape, with long pectoral fins and a knobbly head. It is known for breaching and other distinctive surface behaviors, making it popular with whale watchers. Males produce a complex song lasting 10 to 20 minutes, which they repeat for hours at a time. All the males in a group will produce the same song, which is different each season. Its purpose is not clear, though it may help induce estrus in females.

Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 km (16,000 mi) each year. They feed in polar waters, and migrate to tropical or subtropical waters to breed and give birth, fasting and living off their fat reserves. Their diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net technique.

Like other large whales, the humpback was a target for the whaling industry. The species was once hunted to the brink of extinction; its population fell by an estimated 90% before a 1966 moratorium. While numbers have partially recovered to some 80,000 animals worldwide, entanglement in fishing gear, collisions with ships and noise pollution continue to affect the species.

Humpback whales are rorquals, members of the Balaenopteridae family that includes the blue, fin, Bryde's, sei and minke whales. The rorquals are believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Miocene era. However, it is not known when the members of these families diverged from each other.

Though clearly related to the giant whales of the genus Balaenoptera, the humpback is the sole member of its genus. Recent DNA sequencing has indicated the humpback is actually more closely related to certain rorquals, particularly the fin whale ( B. physalus) and possibly the gray ( Eschrichtius robustus), than it is to others such as the minke.

The humpback was first identified as baleine de la Nouvelle Angleterre by Mathurin Jacques Brisson in his Regnum Animale of 1756. In 1781, Georg Heinrich Borowski described the species, converting Brisson's name to its Latin equivalent, Balaena novaeangliae. In 1804, Lacépède shifted the humpback from the family Balaenidae, renaming it B. jubartes. In 1846, John Edward Gray created the genus Megaptera, classifying the humpback as Megaptera longipinna, but in 1932, Remington Kellogg reverted the species names to use Borowski's novaeangliae. The common name is derived from the curving of their backs when diving. The generic name Megaptera from the Ancient Greek mega- μεγα ("giant") and ptera/ πτερα ("wing"), refers to their large front flippers. The specific name means "New Englander" and was probably given by Brisson due to regular sightings of humpbacks off the coast of New England.

Genetic research in mid-2014 by the British Antarctic Survey confirmed that the separate populations in the North Atlantic, North Pacific and Southern Oceans are more distinct than previously thought. Some biologists believe that these should be regarded as separate subspecies and that they are evolving independently.

Humpbacks can easily be identified by their stocky body, obvious hump, black dorsal coloring and elongated pectoral fins. The head and lower jaw are covered with knobs called tubercles, which are hair follicles and are characteristic of the species. The fluked tail, which typically rises above the surface when diving, has wavy trailing edges.

Humpbacks have 270 to 400 darkly colored baleen plates on each side of their mouths. The plates measure from 18 in (46 cm) in the front to about 3 ft (0.91 m) in the back, behind the hinge.

Ventral grooves run from the lower jaw to the umbilicus, about halfway along the underside of the body. These grooves are less numerous (usually 14-22) than in other rorquals, but are fairly wide.

The female has a hemispherical lobe about 15 cm (5.9 in) in diameter in her genital region. This visually distinguishes males and females. The male's penis usually remains hidden in the genital slit.

Fully grown males average 13-14 m (43-46 ft). Females are slightly larger at 15-16 m (49-52 ft); one large recorded specimen was 19 m (62 ft) long and had pectoral fins measuring 6 m (20 ft) each. The largest humpback on record, according to whaling records, was a female killed in the Caribbean; she was 27 m (89 ft) long with a weight of 90 metric tons (99 short tons), although the reliability of these extremely atypical data is impossible to confirm. The largest measured by the scientists of the Discovery Committee were a female and a male at 14.9 and 14.75 m (48.9 and 48.4 ft) respectively, although this was out of a sample size of only 63 whales. Body mass typically is in the range of 25-30 metric tons (28-33 short tons), with large specimens weighing over 40 metric tons (44 short tons).

The long black and white tail fin can be up to a third of body length.

Several hypotheses attempt to explain the humpback's pectoral fins, which are proportionally the longest fins of any cetacean. The higher maneuverability afforded by long fins and the usefulness of the increased surface area for temperature control when migrating between warm and cold climates may have supported this adaptation. These very long heavy pectoral fins with a row of knuckle-like knobs along their anterior edges are effective weapons in confrontations with killer whales. The large, sharp-cornered barnacle Coronula diadema often attaches there, adding a natural equivalent of knuckledusters. Humpbacks occasionally defend other animals against attack by predators; for example, they were observed interfering to defend a gray whale calf that had just been killed by killer whales.

The varying patterns on the tail flukes distinguish individual animals. Identification is done by comparing the amount of white vs black and scars on the fluke. The humpback whales are then given a catalogue number. A study using data from 1973 to 1998 on whales in the North Atlantic gave researchers detailed information on gestation times, growth rates and calving periods, as well as allowing more accurate population predictions by simulating the mark-release-recapture technique. A photographic catalogue of all known North Atlantic whales was developed over this period and is maintained by College of the Atlantic..

The lifespan of rorquals ranges from 45 to 100 years.

Courtship rituals take place during the winter months, following migration toward the equator from summer feeding grounds closer to the poles. Competition is usually fierce. Unrelated males, dubbed escorts, frequently trail females, as well as cow-calf pairs. Males gather into competitive groups around a female and fight for the right to mate with her. Group size ebbs and flows as unsuccessful males retreat and others arrive. Behaviors include breaching, spyhopping, lob-tailing, tail-slapping, pectoral fin-slapping, peduncle throws, charging and parrying.

Whale song is thought to have an important role in inducing estrus in females and in mate selection; however, it may also be used between males to establish dominance. Humpback whales are polyandrous, with a female having multiple male partners over the course of her lifespan.

Females typically breed every two or three years. The gestation period is 11.5 months. The peak months for birth are January and February in the Northern Hemisphere, July and August in the Southern Hemisphere. Females wait for one to two years before breeding again. Recent research on mitochondrial DNA reveals that groups living in proximity to each other may represent distinct breeding pools. Humpback whale births have been rarely observed. One birth witnessed off Madagascar occurred within four minutes. Humpback whales have been known to hybridize with other rorquals; there is a well-documented report of a humpback- blue whale hybrid in the South Pacific.

Humpbacks are a friendly species that interact with other cetaceans such as bottlenose dolphins. Right whales interact with humpbacks. These behaviors have been recorded in all oceans. Records of humpback and southern right whales demonstrating what were interpreted to be mating behaviors have been documented off the Mozambique and Brazilian coasts. Humpback whales appear in mixed groups with other species, such as the blue, fin, minke, gray and sperm whales. Interaction with gray, fin, and right whales have been observed. Teams of researchers observed a male humpback whale singing an unknown type of song and approaching a fin whale at Rarotonga in 2014. One individual was observed playing with a bottlenose dolphin in Hawaiian waters. Incidents of humpback whales protecting other animals such as seals and other whales from killer whales have been documented and filmed. Studies of such incidents indicate that the phenomenon is species-wide and global, with incidents being recorded at various locations across the world. In September 2017 in Rarotonga, the Cook Islands, snorkeler and whale biologist Nan Hauser reported that two adult humpback whales had protected her from a 4.5 m (15 ft) tiger shark, with one whale pushing her away from the shark while the other used its tail to block the shark's advances.

Both male and female humpback whales vocalize, but only males produce the long, loud, complex "song" for which the species is famous. Each song consists of several sounds in a low register, varying in amplitude and frequency and typically lasting from 10 to 20 minutes. Individuals may sing continuously for more than 24 hours. Cetaceans have no vocal cords, instead, they produce sound via a larynx-like structure found in the throat, the mechanism of which has not been clearly identified. Whales do not have to exhale to produce sound.

Whales within a population sing a single song. All North Atlantic humpbacks sing the same song, while those of the North Pacific sing a different song. Each population's song changes slowly over a period of years without repeating. The songs are culturally transmitted, and have been shown in some cases to spread "horizontally" between neighbouring populations over the course of successive breeding seasons.

Scientists are unsure of the purpose of whale songs. Only males sing, suggesting one purpose is to attract females or to induce estrus in the females. However, many of the whales observed to approach a singer are other males, often resulting in conflict. Singing may, therefore, be a challenge to other males. Some scientists have hypothesized the song may serve an echolocative function. During the feeding season, humpbacks make unrelated vocalizations for herding fish into their bubble nets.

Humpback whales make other sounds to communicate, such as grunts, groans, snorts and barks.

Whales are air-breathing mammals who must surface to get the air they need. The stubby dorsal fin is visible soon after the blow (exhalation) when the whale surfaces, but disappears by the time the flukes emerge. Humpbacks have a 3 m (9.8 ft), heart-shaped bushy blow through the blowholes. They do not generally sleep at the surface, but they must continue to breathe. Possibly only half of their brain sleeps at one time, with one half managing the surface-blow-dive process without awakening the other half.

Migratory patterns and social interactions were explored in the 1960s, and by further studies in 1971. Calambokidis et al. provided the "first quantitative assessment of the migratory structure of humpback whales in the entire North Pacific basin."

Humpbacks inhabit all major oceans, in a wide band running from the Antarctic ice edge to 81°N latitude. The four global populations are North Pacific, Atlantic, Southern Ocean and Indian Ocean populations. These populations are distinct. Although the species has cosmopolitan distribution and is usually not considered to cross the equator line, seasonal observations at Cape Verde suggest possible interactions among populations from both hemispheres. Aside from the Arabian Sea group, year-round presences have been confirmed among British and Norwegian waters. Parts of wintering grounds around the globe have been poorly studied or being undetected, such as around Pitcairn Islands, Northern Mariana Islands (e.g. Marpi and CK Reefs vicinity to Saipan), Volcano Islands, Pasaleng Bay, Trindade and Martin Vaz, Mauritius, and Aldabra.

Whales were once uncommon in the Mediterranean and the Baltic Seas, but have increased their presence in both waters as global populations have recovered. Recent increases within the Mediterranean basin, including re-sightings, indicate that more whales may migrate into the inland sea in the future, not only for wintering but also for feeding. Humpbacks are also showing signs of re-expanding into former ranges, such as Scotland, Skagerrak and Kattegat, as well as Scandinavian fjords such as Kvænangen, where they had not been observed for decades.

In the North Atlantic, feeding areas range from Scandinavia to New England. Breeding occurs in the Caribbean and Cape Verde. In the South Atlantic and Indian Oceans, whales may breed off Brazil, as well the coasts of central, southern and southeastern Africa (including Madagascar). Whale visits into Gulf of Mexico have been infrequent, but occurred in the gulf historically. In the South Atlantic, about 10% of world population of the species possibly migrate to the Gulf of Guinea. Comparison of songs between those at Cape Lopez and Abrolhos Archipelago indicate that trans-Atlantic mixings between western and southeastern populations occur.

A large population spreads across the Hawaiian Islands every winter, ranging from the island of Hawaii in the south to Kure Atoll in the north. These animals feed in areas ranging from the coast of California to the Bering Sea. Humpbacks were first observed in Hawaiian waters in the mid-19th century and might have gained a dominance over North Pacific right whales, as the right whales were hunted to near-extinction. A smaller portion of the north Pacific group migrates in winter to Bahia Banderas, a large bay on the west coast of Mexico in the Puerto Vallarta resort region.

A 2007 study identified seven individuals then wintering off the Pacific coast of Costa Rica as having traveled from the Antarctic-around 8,300 km (5,200 mi). Identified by their unique tail patterns, these animals made the longest documented mammalian migration. In Australia, two main migratory populations were identified, off the west and east coasts. These two populations are distinct, with only a few females in each generation crossing between the two groups.

In Panama and Costa Rica, humpback whales come from both the Southern Hemisphere (July-October with over 2,000 whales) and the Northern Hemisphere (December-March numbering about 300). South Pacific populations migrating off mainland New Zealand, Kermadec Islands, and Tasmania are increasing, but less rapidly than in Australian waters because of illegal whaling by the Soviet Union in the 1970s.

Some recolonizing habitats are confirmed, especially in the North and South Atlantic (e.g. English and Irish coasts, English Channel) to coasts in the north such as the North Sea and Wadden Sea, where the first confirmed sighting since 1755 was made in 2003, South Pacific (e.g. New Zealand coasts and Niue), pelagic islands of Chile such as Isla Salas y Gómez and Easter Island, where possibilities of undocumented wintering grounds have been considered, southern fiords of Chile and Peru (e.g. Gulf of Penas, Strait of Magellan, Beagle Channel) and in Asia, such as in the Philippines, Babuyan Islands, Cagayan (the first modern mortality of the species in the nation was in 2007), Calayan and Pasaleng Bay, the Ryukyu Islands, the Volcano Islands in Japan, the Northern Mariana Islands recently again became stable/growing wintering grounds while the Marshall Islands, Vietnamese, Taiwanese and Chinese coasts show slow or no obvious recovery. In 2020, A whale was spotted wandering in the Saint Lawrence River at Montreal and a Migaloo in Australian waters.

Whales again migrate off Japanese archipelagos and into the Sea of Japan. Connections between these stocks and whales seen in the Sea of Okhotsk, on Kamchatka coasts and around the Commander Islands have been studied. Historical wintering distributions could have been much wider and more southerly distributed, as whales were seen in areas along the Batanes, Sulu and Celebes Seas including off Palawan, Luzon, Malaysia and Mindanao, with higher densities around today's Cape Eluanbi and Kenting National Park. Unconfirmed sightings have been reported near Borneo in modern times. The first confirmation in modern Taiwan was of a pair off Hualien in 1994, followed by a successful escape from entanglement off Taitung in 1999, and continuous sightings around Orchid Island in 2000. Few/none regularly migrate into Kenting National Park. In addition, despite sightings reported almost annually off Green and Orchid Islands, relatively short stays in these waters indicate recoveries as winter foraging has not occurred. Sightings, including of a cow-calf pair, have occurred along the east coast of Taiwan. Around Hong Kong, two documented sightings were recorded in 2009 and in 2016. One of the first documented sightings within the Yellow Sea was of a group of 3 or 4 individuals, including a cow/calf pair in Changhai County in October, 2015.

Since November 2015, whales gather around Hachijō-jima, far north from the known breeding areas in the Bonin Islands. All breeding activities except for giving births had been confirmed as of January, 2016. That makes Hachijo-jima the northernmost breeding ground in the world, north of breeding grounds such as Amami Ōshima, Midway Island, and Bermuda.

A non-migratory population in the Arabian Sea remains there year-round. More typical annual migrations cover up to 25,000 km (16,000 mi), making it one of the most-traveled mammalian species. Genetic studies and visual surveys indicate that the Arabian group is the most isolated of all humpback groups and is the most endangered, numbering possibly fewer than 100 animals. Within the Arabian Sea, Masirah Island and Gulf of Masirah, Halaniyat Islands and Kuria Muria Bay are hot spots for the species.

Whales were historically common in continental and marginal waters such as the Hallaniyat Islands, along Indian coasts, Persian Gulf and Gulf of Aden, and recent migrations into the gulf including by cow-calf pairs. It is unknown whether whales seen in the Red Sea originate in this population, however sightings increased since in 2006 even in the northern part of the sea such as in Gulf of Aqaba. Individuals may reach the Maldives, Sri Lanka, or further east. Humpbacks have been considered rather vagrant into Persian Gulf, however new studies indicate more regular presences can be expected.

Origins of whales occurring at Maldives are not clear either from Arabian or south Pacific populations, and overlaps are possible.

Humpbacks feed primarily in summer and live off fat reserves during winter. They feed only rarely and opportunistically in their wintering waters. The humpback is an energetic hunter, taking krill and small schooling fish such as juvenile Atlantic and Pacific salmon, herring, capelin and American sand lance, as well as Atlantic mackerel, pollock, haddock and Atlantic menhaden in the North Atlantic. They have been documented opportunistically feeding near fish hatcheries in Southeast Alaska, feasting on salmon fry released from the hatcheries. Krill and copepods are prey species in Australian and Antarctic waters.

A whale off Australia on the spring migration, feeding on krill by turning on its side and propelling through the krill

The humpback has the most diverse hunting repertoire of all baleen whales. Its most inventive technique is known as bubble net feeding; a group of whales dive up to 20 m (66 ft) below the surface and swim in a shrinking circle blowing air from their blowholes creating vertical cylinder-ring of bubbles that captures the prey above them. Humpbacks use two main behaviors to create bubble-netting; upward spirals and double loops. Upward spirals involve the whales blowing continuously as they circle towards the surface, creating a spiral of bubble. Double loops consist of a deep, long loop that corrals the prey followed by tail slaps (lobtailing) at the surface and then a smaller loop that serves to make the final capture of the prey. After the nets are created, humpbacks swimming into them with their mouth gaping and ready to shallow. Using network-based diffusion analysis, one study argued that whales learned lobtailing from other whales in the group over a period of 27 years in response to a change in the primary form of prey.

Visible scars indicate that killer whales (orcas) can prey upon juvenile humpbacks, though until recently hunting had never been witnessed and attacks were assumed to be superficial in nature. However, a 2014 study off Western Australia observed that when available in large numbers, young humpbacks can be attacked and sometimes killed by orcas. Moreover, mothers and (possibly related) adults escort neonates to deter such predation. The suggestion is that when humpbacks suffered near-extinction during the whaling era, orcas turned to other prey, but are now resuming their former practice. There is also evidence that humpback whales will defend against or attack killer whales who are attacking either humpback calves or juveniles as well as members of other species. The great white shark is another confirmed predator of the humpback whale. In 2020, Marine biologists Dines and Gennari et al., published a documented incident of a group of great white sharks exhibiting pack-like behavior to successfully attack and kill a live adult humpback whale. A second incident regarding great white sharks killing humpback whales was documented off the coast of South Africa. The shark recorded instigating the attack was a female nicknamed "Helen". Working alone, the shark attacked a 33 ft (10 m) emaciated and entangled humpback whale by attacking the whale's tail to cripple and bleed the whale before she managed to drown the whale by biting onto its head and pulling it underwater.

Humpback whales were hunted as early as the 18th century. By the 19th century, many nations (particularly the United States) were hunting the animal heavily in the Atlantic Ocean and to a lesser extent in the Indian and Pacific Oceans. The late-19th-century introduction of the explosive harpoon allowed whalers to accelerate their take. This, along with hunting in the Antarctic Ocean beginning in 1904, sharply reduced whale populations. During the 20th century, over 200,000 humpbacks were taken, reducing the global population by over 90%. North Atlantic populations dropped to as low as 700 individuals.

In 1946, the International Whaling Commission (IWC) was founded to oversee the industry. They imposed hunting regulations and created hunting seasons. To prevent extinction, IWC banned commercial humpback whaling in 1966. By then, the global population had been reduced to around 5,000. The ban has remained in force since 1966.

Prior to commercial whaling, populations could have reached 125,000. North Pacific kills alone are estimated at 28,000. The Soviet Union deliberately under-recorded its catches; the Soviets reported catching 2,820 between 1947 and 1972, but the true number was over 48,000.

As of 2004, hunting was restricted to a few animals each year off the Caribbean island of Bequia in the nation of St. Vincent and the Grenadines. The take is not believed to threaten the local population. Japan had planned to kill 50 humpbacks in the 2007/08 season under its JARPA II research program. The announcement sparked global protests. After a visit to Tokyo by the IWC chair asking the Japanese for their co-operation in sorting out the differences between pro- and antiwhaling nations on the commission, the Japanese whaling fleet agreed to take no humpback whales during the two years it would take to reach a formal agreement.

In 2010, the IWC authorized Greenland's native population to hunt a few humpback whales for the following three years.

In Japan, humpback, minkes, sperm and many other smaller Odontoceti, including critically endangered species such as North Pacific right, western gray and northern fin, have been targets of illegal captures. The hunts use harpoons for dolphin hunts or intentionally drive whales into nets, reporting them as cases of entanglement. Humpback meat can be found in markets. In one case, humpbacks of unknown quantities were illegally hunted in the Exclusive Economic Zones of anti-whaling nations such as off Mexico and South Africa.

Whale watching is the leisure activity of observing humpbacks in the wild. Participants watch from shore or on touring boats. Humpbacks are generally curious about nearby objects. Some individuals, referred to as "friendlies", approach whale-watching boats closely, often staying under or near the boat for many minutes. Because humpbacks are typically easily approachable, curious, identifiable as individuals and display many behaviors, they have become the mainstay of whale tourism around the world. Hawaii has used the concept of " ecotourism" to benefit from the species without killing them. This business brings in revenue of $20 million per year for the state's economy.

North Atlantic

North Pacific

Southern Hemisphere

Summer

New York, New England, Grand Manan Island, Nova Scotia and Newfoundland, the northern St. Lawrence River, the Snaefellsnes peninsula in the west of Iceland.

Bahía Solano and Nuquí in Colombia, California, Alaska, Oregon, Washington, British Columbia, Isla Iguana in Panama, Ecuador.

Antarctica.

Winter

Samaná Province of the Dominican Republic, the Bay of Biscay France, Mona Passage off the coast of Puerto Rico

Hawaii, Baja California Sur, the Bahía de Banderas off Puerto Vallarta, Ogasawara, Okinawa

Sydney, Byron Bay north of Sydney, Hervey Bay north of Brisbane, North and East of Cape Town, New Zealand especially Kaikoura, the Tongan islands, Victor Harbor and outlying beaches, Saint Helena in the South Atlantic.

In December 1883, a male humpback swam up the Firth of Tay in Scotland, past what was then the whaling port of Dundee. Harpooned during a failed hunt, it was found dead off of Stonehaven a week later. Its carcass was exhibited to the public by a local entrepreneur, John Woods, both locally and then as a touring exhibition that traveled to Edinburgh and London. The whale was dissected by Professor John Struthers, who wrote seven papers on its anatomy and an 1889 monograph on the humpback.

An albino humpback whale that travels up and down the east coast of Australia became famous in local media because of its rare, all-white appearance. Migaloo is the only known Australian all-white specimen and is a true albino. First sighted in 1991, the whale was named for an indigenous Australian word for "white fella". To prevent sightseers approaching dangerously close, the Queensland government decreed a 500-m (1600-ft) exclusion zone around him.

Migaloo was last seen in June 2014 along the coast of Cape Byron in Australia. Migaloo has several physical characteristics that can be identified; his dorsal fin is somewhat hooked, and his tail flukes have a unique shape, with edges that are spiked along the lower trailing side.

In 1985, Humphrey swam into San Francisco Bay and then up the Sacramento River towards Rio Vista. Five years later, Humphrey returned and became stuck on a mudflat in San Francisco Bay immediately north of Sierra Point below the view of onlookers from the upper floors of the Dakin Building. He was twice rescued by the Marine Mammal Center and other concerned groups in California. He was pulled off the mudflat with a large cargo net and the help of the US Coast Guard. Both times, he was successfully guided back to the Pacific Ocean using a "sound net" in which people in a flotilla of boats made unpleasant noises behind the whale by banging on steel pipes, a Japanese fishing technique known as oikami. At the same time, the attractive sounds of humpback whales preparing to feed were broadcast from a boat headed towards the open ocean. He was last sighted in the vicinity of the Farallon Islands in 1991.

Analyses of whale songs in the 1960s led to worldwide media interest and convinced the public that whales were highly intelligent, aiding the antiwhaling advocates.

The worldwide population is estimated at 84,000 and increasing. Regional estimates are 18,000-20,000 in the North Pacific, 12,000 in the North Atlantic and over 50,000 in the Southern Hemisphere, down from a pre whaling population of 125,000.

The NOAA is committed to protecting and recovering the humpback whale. NOAA enacted vessel speed restrictions which serve to protect the endangered North Atlantic right whale and many other species of whales. They respond to dead, injured, or entangled whales. They also educate whale watchers, tourists, and vessel operators on responsible viewing of the humpback whales. NOAA works to develop methods to reduce vessel strikes and reduce risk of entanglement in fishing gear. The NOAA's work will help reduce the number of humpback whale deaths.

In August 2008, the IUCN changed humpbacks' status from Vulnerable to Least Concern, although two subpopulations remain endangered. The United States is considering listing separate humpback populations, so smaller groups, such as North Pacific humpbacks, which are estimated to number 18,000-20,000 animals, might be delisted. This is made difficult by humpbacks' migrations, which can extend 5,157 miles (8,299 km) from Antarctica to Costa Rica. In Costa Rica, the Ballena Marine National Park is designed for humpback protection.

Areas where population data is limited and the species may be at higher risk include the Arabian Sea, the western North Pacific Ocean, the west coast of Africa and parts of Oceania.

The species was listed as vulnerable in 1996 and endangered as recently as 1988. Most monitored stocks have rebounded since the end of commercial whaling. In the North Atlantic stocks are believed to be approaching prehunting levels. However, the species is considered endangered in some countries, including the United States.

A 2008 US Department of Commerce analysis (SPLASH) noted that the many challenges to determining the recovery status included the lack of accurate population estimates, the unexpected complexity of population structures and their migration. The report was based on data collected from 2004 to 2006. At the time, the North Pacific population was some 18,302. The estimate is consistent with a moderate rate of recovery for a depleted population, although it was considered to be a "dramatic increase in abundance" from other post-1960s estimates. By comparison, Calambokidis et al. estimated 9,819, covering 1991-1993. This represents a 4% annual increase in population from 1993 to 2006. The sanctuary provided by US national parks, such as Glacier Bay National Park and Preserve and Cape Hatteras National Seashore, became major factors in population recovery.

Off the west coast of Canada, the Gwaii Haanas National Marine Conservation Area Reserve covers 3,400 square kilometres (1,300 sq mi). It is "a primary feeding habitat" of the North Pacific population. Their critical habitat overlaps with tanker shipping routes between Canada and its eastern trade partners. In 2005 the North Pacific population was listed as threatened under Canada's Species at Risk Act (SARA). On April 19, 2014 the Department of the Environment recommended an amendment to SARA to downgrade their status off the Pacific coast from "threatened" to "species of special concern". According to Committee on the Status of Endangered Wildlife in Canada (COSEWIC), the North Pacific humpback population increased at about 4% annually from 1992 to 2008. Although socioeconomic costs and benefits were considered in their decision to upgrade their status, according to the University of British Columbia's Marine Mammal Research Consortium's research director, the decision was based on biology, not politics.

Whaling no longer threatens the species, but individuals are vulnerable to collisions with ships, entanglement in fishing gear and noise pollution. Like other cetaceans, humpbacks can be injured by excessive noise. In the 19th century, two humpback whales were found dead near sites of repeated oceanic sub-bottom blasting, with traumatic injuries and fractures in the ears.

Saxitoxin, a paralytic shellfish poisoning from contaminated mackerel, has been implicated in humpback whale deaths.

Whale researchers along the Atlantic Coast report that there have been more stranded whales with signs of vessel strikes and fishing gear entanglement in recent years than ever before. The NOAA recorded 88 stranded humpback whales between January 2016 and February 2019. This is more than double the number of whales stranded between 2013 and 2016. Because of the increase in stranded whales NOAA declared an unusual mortality event in April 2017. This declaration still stands. Virginia Beach aquarium's stranding response coordinator, Alexander Costidis says the conclusions are that the two causes of these unusual mortality events are vessel interactions and entanglements.

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Struthers, Sir John (1889). Memoir on the Anatomy of the Humpback Whale, Megaptera Longimana. Maclachlan and Stewart.

Best, P. B. (1993). "Increase rates in severely depleted stocks of baleen whales". ICES Journal of Marine Science. 50 (2): 169-186. doi:10.1006/jmsc.1993.1018.

Smith, T.D.; Allen, J.; Clapham, P.J.; Hammond, P.S.; Katona, S.; Larsen, F.; Lien, J.; Mattila, D.; Palsboll, P.J.; Sigurjonsson, J.; Stevick, P. T.; Oien, N. (1999). "An ocean-basin-wide mark-recapture study of the North Atlantic humpback whale". Marine Mammal Science. 15: 1-32. doi:10.1111/j.1748-7692.1999.tb00779.x. Archived from the original on 2021-06-23.

Franklin, T.; Franklin, W.; Brooks, L.; Harrison, P.; Baverstock, P.; Clapham, P. (2011). "Seasonal changes in pod characteristics of eastern Australian humpback whales (Megaptera novaeangliae), Hervey Bay 1992-2005". Marine Mammal Science. 27 (3): E134-E152. doi:10.1111/j.1748-7692.2010.00430.x.

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The humpback whale ( Megaptera novaeangliae) is a species of baleen whale. It is one of the larger rorqual species, with adults ranging in length from 12-16 m (39-52 ft) and weighing around 25-30 t (28-33 short tons). The humpback has a distinctive body shape, with long pectoral fins and a knobbly head.

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Whales are known for being the largest and most intelligent creatures in the ocean. Now, marine biologists have discovered that they also capture tonnes of carbon from the atmosphere, a service with an economic value of US$1 trillion for all the great whales, according to a study published by the International Monetary Fund.

Up until now, protecting great whales has been viewed as a human good. But the International Monetary Fund research points out that protecting whales also has a monetary incentive, as it turns out whales are an important nature-based solution to capturing carbon from human emissions.

"The carbon capture potential of whales is truly startling," said the report. "Our conservative estimates put the value of the average great whale, based on its various activities, at more than US$2 million, and easily over US$1 trillion for the current stock of great whales."

Whales accumulate carbon in their bodies during their long lives, some of which stretch to 200 years. When they die, they sink to the bottom of the ocean, taking the carbon with them. According to the study, each great whale sequesters around 33 tonnes of carbon dioxide on average. A tree during the same period only contributes to 3 per cent of the carbon absorption of the whale.

Wherever whales are found, so are phytoplankton. These tiny creatures produce every second breath we take, by contributing to at least 50 per cent of all the oxygen in our atmosphere. They also capture about 37 billion tonnes of carbon dioxide or four Amazon forests' worth. Whale poop has a multiplier effect on phytoplankton as it contains iron and nitrogen, the elements phytoplankton need to grow; so, the more whales, the more oxygen.

"The findings of the International Monetary Fund report clearly show the amazing connections between some of the smallest and largest examples of life on our planet-and the importance of understanding these complex relationships not only for their intrinsic value but for the vital role nature plays in keeping us alive too," said Doreen Robinson, wildlife expert at the UN Environment Programme.

Whale populations are today a smidgen of what they once were. Biologists estimate that there are slightly more than 1.3 million whales in the ocean, a quarter of their pre-whaling number of 4 to 5 million. Some species in particular, like the blue whale, are only 3 per cent of what they used to be. To preserve and protect whale populations, we must reduce the many dangers to whales in our seas.

One way to do so would be to apply the UN-REDD Programme model for protecting forests. Recognizing that deforestation accounts for 17 per cent of carbon emissions, the UN-REDD Programme gives incentives to countries to preserve their forests as a way of keeping carbon dioxideout of the atmosphere.

"In a similar way, we can create financial mechanisms to promote the restoration of the world's whale populations," said the report's authors. "Incentives in the form of subsidies or other compensation could help those who incur significant costs as a result of whale protection. For example, shipping companies could be compensated for the cost of altered shipping routes to reduce the risk of collisions."

With the Paris Agreement coming into force next year and the effects of climate change ever more prevalent, we must prevent or reverse the harm to global whale populations now. Researchers estimate that unless new methods are put forward, it would take over 30 years to double the number of current whales, and several generations to return them to their pre-whaling numbers. "Society and our own survival can't afford to wait this long," they said.

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Whales are known for being the largest and most intelligent creatures in the ocean. Now, marine biologists have discovered that they also capture tonnes of carbon from the atmosphere, a service with an economic value of US$1 trillion for all the great whales, according to a study published by the International Monetary Fund.

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10 good reasons to protect whales - Greenpeace Africa

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Killing whales for food has been happening for millennia. But it was commercial whaling - turning whales into barrels of oil for profit - that led to the wholesale destruction of most of the world's populations of big whales.The loss of whales from our oceans is the same story as overfishing of big fish - sharks, tuna, cod and others.

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Molluscs (or mollusks) are an important phylum of invertebrate animals. Most of them are marine. They have huge numbers in-shore, that is, in shallow waters near the shore. They are the largest marine phylum, with about 85,000 living species, 23% of all named marine organisms. They also occur in freshwater and on land.

Molluscs are extremely varied: they have great diversity. That may be why there is no word in English for the phylum as a whole. "In an evolutionary sense, molluscs are plastic material". They have much more variety than their ancient rivals, the brachiopods.

Most molluscs have shells, but some groups do not: octopods, slugs, and the gastropods known as sea slugs.

Many molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and in anatomical structure, but also in behaviour and in habitat.

The phylum is usually divided into 9 or 10 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish and octopus, are among the most neurologically advanced of all invertebrates: they have good brains and complex behaviours. Either the giant squid or the colossal squid is the largest known invertebrate species. The gastropods ( snails and slugs) are by far the most numerous molluscs in terms of classified species, and account for 80% of the total. The scientific study of molluscs is called malacology.

Main features

The three most universal features defining modern molluscs are:

1. a mantle with a cavity used for breathing and excretion,

2. the presence of a radula, and

3. the structure of the nervous system.

Other than these things, molluscs have so much variety that many textbooks use a "hypothetical ancestral mollusc" to summarise them (see below). This has a single, " limpet-like" shell on top, which is made of proteins and chitin reinforced with calcium carbonate. It is secreted by a mantle covering the whole upper surface. The underside of the animal consists of a single muscular "foot".

The mollusc's feeding system starts with a rasping "tongue", the radula. The complex digestive system uses mucus and microscopic, muscle-powered "hairs" called cilia. The generalized mollusc has two paired nerve cords, or three in bivalves. The brain, in species that have one, circles the oesophagus. Most molluscs have eyes, and all have sensors to detect chemicals, vibrations, and touch. The simplest type of molluscan reproductive system relies on external fertilization, but more complex variations occur. All produce eggs, from which may emerge trochophore larvae, more complex veliger larvae, or miniature adults.

A striking feature of molluscs is the use of the same organ for multiple functions. For example, the heart and nephridia ("kidneys") are important parts of the reproductive system, as well as the circulatory and excretory systems. In bivalves, the gills both "breathe" and produce a water current in the mantle cavity: this is important for excretion and reproduction. In reproduction, molluscs may change gender to accommodate the other breeding partner.

Good evidence exists for the appearance of gastropods, cephalopods and bivalves in the Cambrian period, 541 to 485.4 million years ago (mya). Before that, the evolutionary history of molluscs' emergence from the ancestral Lophotrochozoa is still unclear.

Mollusc species can also represent hazards or pests for human activities. The bite of the blue-ringed octopus is often fatal, and that of Octopus apollyon causes inflammation that can last for over a month. Stings from a few species of large tropical cone shells can also kill: their venoms have become important tools in neurological research. Schistosomiasis (also known as bilharzia, bilharziosis or snail fever) is transmitted to humans via water snail hosts, and affects about 200 million people. Snails and slugs can also be serious agricultural pests, and accidental or deliberate introduction of some snail species into new environments has seriously damaged some ecosystems.

A "generalized mollusc"

Because of the great range of anatomical diversity among molluscs, many textbooks start the subject of molluscan anatomy by describing what is called an archi-mollusc, hypothetical generalized mollusc, or hypothetical ancestral mollusc ( HAM) to illustrate the most common features in the phylum. The picture is rather similar to modern monoplacophorans: some think it may resemble very early molluscs.

The generalized mollusc is bilaterally symmetrical and has a single, " limpet-like" shell on top. The shell is secreted by a mantle covering the upper surface. The underside consists of a single muscular "foot". The visceral mass, or visceropallium, is the soft, nonmuscular metabolic region of the mollusc. It contains the body organs.

Classes of molluscs:

Helcionelloida

It has become clear that the fossil taxon Helcionelloida does not belong to the class Gastropoda. It is now a separate class in the Mollusca. Parkhaev (2006, 2007) created the class Helcionelloida, whose members were previously treated as "Paleozoic molluscs of uncertain systematic position" by Bouchet & Rocroi.

Human interaction

For millennia, molluscs have been a source of food for humans, as well as important luxury goods, notably pearls, mother of pearl, Tyrian purple dye, sea silk, and chemical compounds. Their shells have also been used as a form of currency in some preindustrial societies. A number of species of molluscs can bite or sting humans, and some have become agricultural pests.

Uses by humans

Molluscs, especially bivalves such as clams and mussels, have been an important food source since at least the advent of anatomically modern humans, and this has often resulted in overfishing. Other commonly eaten molluscs include octopuses and squids, whelks, oysters, and scallops. In 2005, China accounted for 80% of the global mollusc catch, netting almost 11,000,000 tonnes (11,000,000 long tons; 12,000,000 short tons). Within Europe, France remained the industry leader. Some countries regulate importation and handling of molluscs and other seafood, mainly to minimize the poison risk from toxins that can sometimes accumulate in the animals.

Most molluscs with shells can produce pearls, but only the pearls of bivalves and some gastropods, whose shells are lined with nacre, are valuable. The best natural pearls are produced by marine pearl oysters, Pinctada margaritifera and Pinctada mertensi, which live in the tropical and subtropical waters of the Pacific Ocean. Natural pearls form when a small foreign object gets stuck between the mantle and shell.

The two methods of culturing pearls insert either "seeds" or beads into oysters. The "seed" method uses grains of ground shell from freshwater mussels, and overharvesting for this purpose has endangered several freshwater mussel species in the southeastern United States. The pearl industry is so important in some areas, significant sums of money are spent on monitoring the health of farmed molluscs.

Other luxury and high- status products were made from molluscs. Tyrian purple, made from the ink glands of murex shells, "fetched its weight in silver" in the fourth century BC, according to Theopompus. The discovery of large numbers of Murex shells on Crete suggests the Minoans may have pioneered the extraction of "imperial purple" during the Middle Minoan period in the 20th-18th centuries BC, centuries before the Tyrians. Sea silk is a fine, rare, and valuable fabric produced from the long silky threads ( byssus) secreted by several bivalve molluscs, particularly Pinna nobilis, to attach themselves to the sea bed. Procopius, writing on the Persian wars circa 550 CE, "stated that the five hereditary satraps (governors) of Armenia who received their insignia from the Roman Emperor were given chlamys (or cloaks) made from lana pinna. Apparently, only the ruling classes were allowed to wear these chlamys."

Mollusc shells, including those of cowries, were used as a kind of money (shell money) in several preindustrial societies. However, these "currencies" generally differed in important ways from the standardized government-backed and -controlled money familiar to industrial societies. Some shell "currencies" were not used for commercial transactions, but mainly as social status displays at important occasions, such as weddings. When used for commercial transactions, they functioned as commodity money, as a tradable commodity whose value differed from place to place, often as a result of difficulties in transport, and which was vulnerable to incurable inflation if more efficient transport or "goldrush" behavior appeared.

Bioindicators

Bivalve molluscs are used as bioindicators to monitor the health of aquatic environments in both fresh water and the marine environments. Their population status or structure, physiology, behaviour or the level of contamination with elements or compounds can indicate the state of contamination status of the ecosystem. They are particularly useful since they are sessile so that they are representative of the environment where they are sampled or placed. Potamopyrgus antipodarum is used by some water treatment plants to test for estrogen-mimicking pollutants from industrial agriculture.

Harmful to humans

Stings and bites

Some molluscs sting or bite, but deaths from mollusc venoms total less than 10% of those from jellyfish stings.

All octopuses are venomous, but only a few species pose a significant threat to humans. Blue-ringed octopuses in the genus Hapalochlaena, which live around Australia and New Guinea, bite humans only if severely provoked, but their venom kills 25% of human victims. Another tropical species, Octopus apollyon, causes severe inflammation that can last for over a month even if treated correctly, and the bite of Octopus rubescens can cause necrosis that lasts longer than one month if untreated, and headaches and weakness persisting for up to a week even if treated.

All species of cone snails are venomous and can sting painfully when handled, although many species are too small to pose much of a risk to humans, and only a few fatalities have been reliably reported. Their venom is a complex mixture of toxins, some fast-acting and others slower but deadlier. The effects of individual cone-shell toxins on victims' nervous systems are so precise as to be useful tools for research in neurology, and the small size of their molecules makes it easy to synthesize them.

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Molluscs (or mollusks) are an important phylum of invertebrate animals. Most of them are marine. They have huge numbers in-shore, that is, in shallow waters near the shore. They are the largest marine phylum, with about 85,000 living species, 23% of all named marine organisms. They also occur in freshwater and on land.

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The Whales Online team asked these questions to researchers who dedicate their time and energy studying the whales of the St. Lawrence. A summary of their responses follows.
Like all living beings, whales occupy a role in the food chain and thus contribute to the balance of the marine ecosystem. As predators, they feed on fish and invertebrates; as prey, they may be hunted by other predators (sharks, whales, etc.) and by Man. When they die, their carcasses sink and serve as food to a host of scavenger organisms who decompose them into nutrients available for other organisms, explains Véronique Lesage of Fisheries and Oceans Canada. Whales act like a pump that recirculates the fish and zooplankton that they've ingested toward the surface in the form of nitrogen-rich fecal matter. These nutrients are essential to the primary production of the marine ecosystem.

Whales are sentinels of the health of marine environments. They are found in all the world's oceans, from coastal areas to the deep sea. As whales lie at the top of the food pyramid, any decline or increase in their population is an indication of a change in their habitat. Dany Zbinden of the organization Mériscope stresses the importance of protecting whales, as doing so will not only ensure the recovery of their own populations, but also the survival of other species in the marine ecosystem. Studying whales has led to numerous discoveries. To this day they serve as an inspiration in the development of new technologies such as watercraft sonar and wind turbine blades.

Moira Brown of the New England Aquarium also points out the commercial importance of whales. Whether through population census programs for recovery plans or observation activities catered to tourists, whales contribute to local economies thanks to people's growing interest in them around the globe. Human activities such as chemical and noise pollution, entanglement in fishing gear and ship strikes have greatly affected whale populations. Canada has the longest coastline in the world. Bordered by three oceans, the marine ecosystem is part of the country's heritage. If humans threaten these populations by breaking the balance of the cycle, they must protect them in order that future generations can observe them and be inspired by them.
Special thanks to Véronique Lesage (Fisheries and Oceans Canada), Dany Zbinden (Mériscope) and Moira Brown (New England Aquarium) for their replies.
To learn more:

Nutrient pumping system in whales: The Whale Pump

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Why are whales important? Why should we protect them? - Baleines en direct

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The Whales Online team asked these questions to researchers who dedicate their time and energy studying the whales of the St. Lawrence. A summary of their responses follows. Like all living beings, whales occupy a role in the food chain and thus contribute to the balance of the marine ecosystem.

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Sperm whales are considered a cosmopolitan species, meaning their range extends across all or most of the world in appropriate habitats. They can be found in areas from the poles to the equator, in all oceans and in the Mediterranean Sea.
WHY THEY ARE IMPORTANT
Like other whale species, sperm whales play a very important role in the health of marine ecosystems by maintaining a stable food chain and ensuring that certain animal species do not overpopulate the ocean. Scientific studies of whales and other cetacean species have also led to many discoveries regarding issues such as echolocation, aquatic environments, marine life and marine mammal intelligence. In 2010, Australian researchers found that the iron-rich feces of sperm whales, together with the pushing of nutrients from the deep ocean to the surface (which enhances nutrient cycling), boosts the growth of phytoplankton, which are marine plants that suck in carbon dioxide from the atmosphere. This makes them responsible for removing an estimate of 400,000 tons of carbon each year. Finally, eco-tourism activities centered around whale watching are becoming more popular and can help growing economies to develop sustainable tourism practices.
HOW THEY ARE THREATENED
Sperm whales were commercially hunted up until the 1970s. They were targeted for oil and ambergris, a substance that forms around squid beaks in a whale's stomach and that was a very valuable substance once used in perfumes. Like most species exploited during the whale hunting days, their numbers have slowly recovered since they became officially protected. Unfortunately, they are now victims of the huge amounts of plastic waste found in our oceans. In late 2018, a dead sperm whale found in the coast of eastern Indonesia had consumed more than six kilograms of plastic, including 115 drinking cups, 25 plastic bags, plastic bottles and flip-flops. Other pollutants, such as oil spills, also pose a threat to the whales.

CITES listing: Sperm whales are listed on Appendix I and Appendix II, meaning trade is sometimes allowed but must be controlled in order to avoid utilization incompatible with their survival.
HOW YOU CAN HELP
Make sure you go on whale watching tours from a reputable operation, many of which tend to participate in whale research. You can also join organisations that work to protect sperm whales. They often have "adopt a whale" programmes, which make great gifts for children or whale lovers.
Read about photographer and #WildForLife champion Cristina Mittermeier's connection to sperm whales in here interview here!

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WHERE THEY CAN BE FOUND Sperm whales are considered a cosmopolitan species, meaning their range extends across all or most of the world in appropriate habitats. They can be found in areas from the poles to the equator, in all oceans and in the Mediterranean Sea. WHY THEY ARE IMPORTANT

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To translate these services into numbers, experts attribute a price to the value of a whale as a function of the services it renders to humanity. This approach is very focused on the direct benefits to humans, also known as anthropocentrism! But it is also an effective way of holding a meaningful conversation that bridges economics, science and conservation.

On average, a cetacean the size of a grey whale would be worth a whopping $2 million, according to the report produced by the International Monetary Fund (IMF). "By sequestering carbon in the ocean, cetaceans can help humanity fight climate change - an ecosystem service that could be worth millions of dollars per whale," economists say.

"I think it's a very good first step toward recognizing that they provide services and that these services are worth something. Potentially, a lot of money!" explains Fabio Berzaghi, lead author of the study. He further states that the IMF's analysis raises an extremely important point about megafauna: that their ecosystem services benefit everyone!

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What good are whales? - Baleines en direct

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To translate these services into numbers, experts attribute a price to the value of a whale as a function of the services it renders to humanity. This approach is very focused on the direct benefits to humans, also known as anthropocentrism! But it is also an effective way of holding a meaningful conversation that bridges economics, science and conservation.

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https://saveourseas.com/why-are-sharks-important/