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How are humans contributing to this problem?

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How are humans contributing to this problem?

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People spread red swamp crayfish primarily by illegal release: of aquarium pets, of biological specimens, after improper use and disposal of live bait.

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Red Swamp Crayfish (Procambarus clarkii)

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Red swamp crayfish are crustaceans with long antennae, two pincer claws, and eight legs. They can grow up to five inches long. The body is dark red, the underside of the tail has a thick black stripe, and the claws and sides have raised red spots.

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Which organisms are impacted by this issue?

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Which organisms are impacted by this issue?

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native macrophages, amphibians, mollusks, macro invertebrates, and fish.

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every continent except Antarctica.

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Invasion History

First Non-native North American Tidal Record: 1955
First Non-native West Coast Tidal Record: 1959
First Non-native East/Gulf Coast Tidal Record: 1955

General Invasion History:

Procambarus clarkii, the Red Swamp Crayfish, is native to the Mississippi and Gulf of Mexico drainages from Florida, Mexico (the Rio Grande/Rio Bravo basin), and New Mexico north to Ohio and Illinois (Hobbs 1989; Campos et al. 1992). It is primarily found in marshes, swamps, and slow-flowing rivers, and is tolerant of hypoxic conditions, poor water quality, and salinities up to 20 PSU (Huner and Barr 1991). It is now the most cosmopolitan crayfish species. Procambarus clarkii was listed as being introduced in 12 states by Hobbs et al. (1989) and 14 states by Taylor et al. (1996). Currently, it is introduced and established in at least 21 US states (Cooper et al. 1998; Taylor et al. 1996; Lieb et al. 2011; USGS Nonindigenous Aquatic Species Program 2011). This crayfish is widely cultured as food, and sometimes used as bait, an aquarium pet, or a laboratory animal for teaching and research (Huner and Barr 1991; Hobbs et al. 1989; Larson and Olden 2008). It has been introduced into every continent except Antarctica. It is well established in France, Italy, Spain, Portugal, Japan, China, Taiwan, Kenya, and Brazil, among other countries (Hobbs et al. 1989, Huner and Barr 1984; Huner and Barr 1991; Taylor et al. 1996; Kawai and Kobayashi 2005).

North American Invasion History:

Invasion History on the West Coast:

Procambarus clarkii was introduced to California by 1924 near Pasadena, and was reared near San Diego in 1932 (Riegel 1959; Cohen and Carlton 1995). By 1959, P. clarkii was widely established in California non-tidal watersheds. It was found in the watershed near the Sacramento San Joaquin Delta (Riegel 1959), and was established by 1966 (Hazel and Kelly 1966, cited by Cohen and Carlton 1995). Two records in or near tidal wetlands are from Tembladero Slough near the Salinas River mouth and Monterey Bay (Riegel 1959) and from the Sweetwater River National Wildlife Refuge at the head of San Diego Bay (2005, USGS Nonindigenous Aquatic Species Program 2011).

Procambarus clarkii has become established in at least 13 lakes in the Puget Sound drainage, Washington State, since 2000, and three streams in Oregon (two Willamette River tributaries, and one Umpqua River tributary, USGS Nonindigenous Aquatic Species Program 2011). A single specimen was collected near Kenai, Alaska, in 2004 (USGS Nonindigenous Aquatic Species Program 2011).

Invasion History on the East Coast:

Isolated collections of Procambarus clarkii are known from interior watersheds in New England and New York, the Sebasticook River between Benton and Burnham, Maine, and from private ponds in Rhode Island (1 specimen, Crocker 1979), Long Island and the lower Hudson Valley (USGS Nonindigenous Aquatic Species Program 2011). Red Swamp Crayfish have been collected in or near tidal wetlands in the Delaware River, Chesapeake Bay, and North Carolina estuaries (Cooper et al. 1998; Kilian et al. 2009; Lieb et al. 2011). They are known to be introduced and present in South Carolina, Georgia, and Florida (Huner 1986; USGS Nonindigenous Aquatic Species Program 2011), but specific records from estuarine areas are not available.

Delaware River estuary- Procambarus clarkii was found in Long Hook Creek, adjacent to the tidal Delaware River, near Philadelphia, Pennsylvania, in 2007. It was also present at two Piedmont sites in the Schuylkill River drainage (Lieb et al. 2011).

Chesapeake Bay- Procambarus clarkii was first introduced to the Chesapeake Bay watershed in 1963, in the Patuxent National Wildlife Refuge. It is now common in the freshwater portions of the lower Patuxent watershed (Arnold Norden 1995, personal communication; Kilian et al. 2009; Kilian et al. 2010). In 1981, the Worcester County Soil Conservation Service began trials of crayfish aquaculture on the Eastern Shore of Maryland (Associated Press 1986; Kilian et al. 2009). In 2007, established populations of P. clarkii were found at 33 locations in the Chesapeake Bay watershed, most of them near seven known crayfish aquaculture operations (Kilian et al. 2009). The distribution of P. clarkii is not well-known in Virginia, but one specimen was collected in 1972 in the York-Pamunkey drainage (USNM 133668), and another in the Potomac watershed in 1992 (USNM 192902, US National Museum of Natural History 2011), both within about 5 km of tidal waters.

North Carolina Estuaries- Huner (1986) listed North Carolina as one of many states to which P. clarkii had been introduced, but gave no details. In 1997-1998, Cooper et al. (1998) collected P. clarkii in many Coastal Plain locations, including two which appear to be in or near tidal wetlands (Horsepen Swamp, Pamlico River drainage and Wilmington, Burnt Mill Creek, a tributary of the Cape Fear River tributary). Additional North Carolina records are reported by the USGS Nonindigenous Species Program (2011), and indicate that this crayfish is widespread in tributaries of Albermarle and Bogue Sound.

Invasion History on the Gulf Coast:

Procambarus clarkii is native to the Gulf Coast from the Rio Grande, Mexico and the Rio Bravo, Texas to the Pensacola Bay drainage in Florida (Hobbs 1989; Huner and Barr 1991). This crayfish has been introduced to Pasco County, north of Tampa Bay (in 1955, Franz and Franz 1990; Taylor et al. 1996), and probably occurs elsewhere on the Florida Peninsula.

Invasion History in Hawaii:

Crayfish (initially thought to be Pacifastacus leniusculus, Signal Crayfish) were introduced from California to Oahu, Hawaii in 1923 and 1927. In 1937 and 1939, 3,225 crayfish were transplanted from Oahu to the islands of Hawaii and Maui. These crayfish were apparently all Procambarus clarkii, and are now found on all of the major Hawaiian Islands (Brock 1960). This crayfish was collected near areas of tidal influence in a survey of streams in Oahu (Englund et al. 2000).

Invasion History Elsewhere in the World:

In Mexico, Procambarus clarkii has been introduced to the Colorado River delta, a number of Pacific tributaries along the Baja California peninsula, and the Rio Culiacan, Sinaloa. In the last two decades, the range of P. clarkii in Mexico has greatly expanded (Campos 1992; Hernandez et al. 2008). It has been widely introduced to Caribbean Islands (Puerto Rico, Dominican Republic), Central America (Guatemala, Belize, Nicaragua, Costa Rica) and South America (Colombia, Venezuela, Ecuador, Brazil) (Hobbs et al. 1989; Huner and Barr 1991; Invasive Species Specialist Group 2011).

In Europe, P. clarkii was first introduced to Spain in 1973, where it is now widespread. Populations are most dense in southern Europe (Spain, Portugal, Italy), but scattered populations are found in England, Belgium, Germany, Poland, Switzerland and Austria, as well as the Azores and Madiera (Holdich et al. 2009). Invaded habitats include brackish coastal wetlands in Italy, Portugal, and Spain (Scalici et al. 2010; Invasive Species Specialist Group 2011).

The Red Swamp Crayfish is widespread in Africa (Egypt, Sudan, Kenya, Uganda, Zimbabwe, South Africa) and Asia (Israel, China, Taiwan, Japan, the Philippines) (Hobbs et al. 1989). In Japan, P. clarkii was first imported as food for Bullfrogs ( Rana catesbiana) in a private pond in Kamkura City, Honshu in 1922. It is now found in at least 20 bodies of water on Kyuhsu, Honshu, and Hokkaido (Kawai and Kobayashi 2005). Procambarus clarkii was introduced from Japan to Nanjing, China, in 1929, and is now widespread in most provinces across the country. The low genetic diversity of P. clarkii is consistent with a single or very few introductions, and constitutes a 'genetic bottleneck' (Yue et al. 2010).

Description

Procambarus clarkii, the Red Swamp Crayfish, has an ovoid carapace and chelae (claws) covered with tubercles and granules. It has a prominent rostrum, which is strongly triangular with a median keel and a pointed tip. The chelae are large and elongated, and have a large gap at the base of the movable finger. The carpus or wrist joint bears three spines, one very large, on its interior edge. In the males, the 3rd segment (ischia) of the 3rd pair of walking legs bears copulatory hooks. The annulus ventralis (seminal receptacle) of the female is an ovoid structure located between the 4th and 5th pair of walking legs, with a sigmoid (a reverse-S shaped) groove running across the center, and two tubercles at the anterior border. The adults are dark red or reddish-brown, with bright red tubercles and a wedge-shaped black stripe on the abdomen (Riegel 1959). These crayfish mature at 57 to 110 mm. The largest reported specimen, from Kenya, was 160 mm (Huner and Barr 1991).

Taxonomy

Cambarus clarkii (Girard, 1852)

Ecology

General:

Life History- Procambarus clarkii is considered a 'tertiary burrowing' crayfish (primary burrowers burrow year-round, secondary burrowers leave the burrow during rainy periods, and tertiary burrowers inhabit the burrow during the breeding season and during droughts, but are found in open water the rest of the year). Freshwater crayfishes, of the family Cambaridae, mate by internal fertilization, with the male inserting pleopods into the females seminal (annulus ventralis) between the 4th and 5th walking legs. The female curls her abdomen far forward, to create a chamber in which the eggs are driven by the pleopods. The mass of eggs becomes attached under the tail. Larval development takes place inside the egg and the young hatch as miniature adults (Barnes 1983).

Male cambarid crayfish show sharp morphological changes with season. At the start of the breeding season, they molt into a sexually competent stage (Form I), marked by lengthening and stiffening of the modified 1st pleopods, more pronounced ischial spines (in the basal segments of the 3rd walking leg) and enlarged chelipeds. After breeding, the crayfish molts back into Form II, with the 1st pleopods less differentiated and soft, ischial spines reduced, and less robust chelipeds (Hobbs 1989).

Ecology- Procambarus clarkii constructs burrows near the water's edge which are usually under 0.5 m in length, but may extend to 4.5 m depending on soil and moisture conditions. Burrows are often partly filled with water, but crayfish are frequently out of the water because of low oxygen concentrations (Correia and Ferreira 1995; Huner and Barr 1984). Overland movements may occur in response to heavy rains, flooding, or anoxia in burrow water (Huner 1989). In the early part of its life, it is found in deeper water (up to two or three feet) in marsh lagoons. As it attains maturity, and the spawning season approaches, it migrates to the shallow water of open marshes (usually less than six inches deep). Culture ponds are usually 0.3-0.7 m deep (Huner and Barr 1991). These crayfish tolerate salinities of 20-30 PSU. In Italy and Portugal, they have become abundant in brackish wetlands and lagoons (Huner and Barr 1991; Scalici et al. 2010).

Food:

detritus; carrion; vascular plants; invertebrates

Consumers:

Fish, mammals, birds, crabs

Competitors:

Other crayfishes, crabs

Trophic Status:

Omnivore

Omni

Habitats

Tolerances and Life History Parameters

Minimum Temperature (ºC)

3

Procambarus clarkii cannot survive freezing conditons F in air, water, or burrows (field observations, Huner and Barr 1991). However, in experiments, P. clarkii survived for 200 days at 3 C, with ~10% mortality (Vesely et al. 2018).

Maximum Temperature (ºC)

39

Procambarus clarkii cannot survive much above 95 F in air or water (field observations, Huner and Barr 1991)

Maximum Salinity (‰)

30

Salinity- Procambarus clarkii survived 3-4 weeks at 20 PSU (Huner and Barr 1991). A population in a brackish lagoon in Italy survivess at salinities of 16-30 PSU (Scalici et al. 2010).

General Impacts

Economic Impacts

Fisheries- Due to its large size, hardiness, rapid growth, and prolific reproduction, Procambarus clarkii is the crayfish most frequently cultured, fished, sold, and eaten in the United States and throughout most of its introduced range. It is the 'Crawdad' of Cajun cooking and more than 125,000 acres of land in Louisiana is used for crayfish farming, and more than 10,000 acres in other states (Huner and Barr 1991). In years with normal rainfall cycles, the ratio between farmed and wild-caught crayfish harvests is about 40%:60%, but wild harvest decreases in years with abnormal weather. The farmed harvest in Louisiana is ~ 28,350 tonnes/yr. At an average price of ~ 50 cents/lb, an average total annual harvest for Louisiana is worth on the order of $50 million per year (calculated from Huner and Barr 1991). In China, the harvest was 300,000 tonnes in 2008 (Yue et al. 2010).

Crayfish may negatively impact fisheries by destroying aquatic vegetation, eating fish in nets, damaging nets, etc. (Huner and Barr 1991; Yue et al 2010). In Lake Navaisha, Kenya, introduced P. clarkii contributed to the rapid growth of an introduced Largemouth Bass ( Micropterus salmoides) population, but then aided its decline through destruction of underwater vegetation and bioturbation of sediment during foraging, reducing water quality for the bass (Britton et al. 2010).

Agriculture- The burrowing activity of Procambarus clarkii can damage crops, such as rice and taro, and may weaken earthen irrigation dams and levees. Further, this crayfish may eat some types of crops. Problems are especially great where crayfish are not eaten for cultural reasons (e.g. Japan, Kenya), however, even where there is large-scale harvesting (e.g. Spain, Portugal, China), damage to rice fields is considerable (Brock 1960; Correia and Ferreira 1995; Huner and Barr 1991; Yue et al. 2010). Red Swamp Crayfish are considered a serious pest in rice fields of the Sacramento-San Joaquin Delta (Riegel 1959; Cohen and Carlton 1995).
Ecological Impacts
Competition- Procambarus clarkii is considered a serious competitor with native crayfish ( Astacus astacus, Austropotomobius pallipes and A. torrentium) in Spain, France, and Italy, through aggression and predation (Holdich et al. 2009). In experiments conducted in Delaware, P. clarkii displaced the native P. acutus acutus from shelters (Gherardi and Daniels 2004).

Habitat Change - Burrowing by P. clarkii has been known to undermine riverbanks, levees, dikes, etc., increasing erosion and suspended sediment. Procambarus clarkii appears to have larger impacts due to burrowing than most other crayfishes, because of its large size and rapid reproduction (Hobbs et al. 1989; Correia and Ferreira 1995; Hobbs et al. 1989). In Lake Navaisha, Kenya, it, together with the introduced fish Cyprinus carpio (Common Carp) is believed to have adversely affected fish habitat through destruction of vegetation and bioturbation, resulting in a decline of the introduced Largemouth Bass ( Micropterus salmoides).

Procambarus clarkii can affect habitats through consuming and destroying underwater plants and through bioturbation during foraging, suspending sediments and releasing nutrients. In Coyote Hills Marsh, Alameda, Procambarus clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata), reducing habitat for attached organisms and cover for prey species (Feminella and Resh 1989, cited by Cohen and Carlton 1995).

Food/Prey- Procambarus clarkii, as a large, introduced crayfish in shallow waters, may be beneficial to some predators. It was deliberately introduced to Patuxent National Wildlife Research Center, Maryland, in 1963, as food for wading birds (Kilian et al. 2009). In the Guadalquivir marshes, Spain, increased feeding on P. clarkii was associated with population increases in 41 species of birds (Tablado et al. 2010). In Lake Navaisha, Kenya, the introduced Largemouth Bass ( Micropterus salmoides) initially increased due to feeding on P. clarkii, but later declined, apparently due to decreased water clarity and habitat quality, attributed in part to impacts of P. clarkii.

Herbivory- Procambarus clarkii is largely herbivorous, consuming submerged and emergent aquatic plants (Huner and Barr 1991). In Coyote Hills Marsh, Alameda, California P. clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata) (Feminella and Resh 1989, cited by Cohen and Carlton 1995). In Lake Navaisha, Kenya, P. clarkii greatly reduced submerged vegetation, adversely affecting fisheries (Huner and Barr 1991; Britton et al. 2010).

Parasitism (Vector)- In southern Europe, P. clarkii has contributed to the spread of the crayfish plague fungus ( Aphanomyces astaci) (Holdich et al. 2009).

Regional Impacts

Procambarus clarkii is reported to support commerical fisheries in the Delta, but may largely be taken incidentally for food and bait (Cohen and Carlton 1995).

Agriculture- Procambarus clarkii damages dikes and levees in rice fields (Riegel 1959; Cohen and Carlton 1995).

Burrowing by Procambarus clarkii is destructive to riverbanks, dikes and levees (Cohen and Carlton 1995).

Aquaculture of P. clarkii began on the Eastern Shore of Maryland in 1981. By 1986, commercial crayfish farming had become widespread in ponds on the lower Delmarva peninsula in MD and VA. The number of farmers grew from about 8 to about 45 between 1980 and 1986. The 1986 harvest was expected to be 12,000 lbs, selling at an average wholesale price of $2.10/lb, or ~ $25,000. The crayfish were sold locally and also exported. Most of the crop goes to Baltimore restaurants (Associated Press 1986). By 2009, only two operations were known in Maryland, although some may be unregistered (Kilian et al. 2009).

In Coyote Hills Marsh, Alameda, Procambarus clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata) (Feminella and Resh 1989, cited by Cohen and Carlton 1995).

In Coyote Hills Marsh, Alameda, Procambarus clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata), reducing habitat for attached organisms and cover for prey species (Feminella and Resh 1989, cited by Cohen and Carlton 1995).

Red Swamp Crayfish were removed from the San Mateo Creek Lagoon, and were treated as a threat to native fishes, particularly the Southern Tidewater Goby ( Eucyclogobius kristinae).

Red Swamp Crayfish were removed from the San Mateo Creek Lagoon, and were treated as a threat to native fishes, particularly the Southern Tidewater Goby ( Eucyclogobius kristinae).

Red Swamp Crayfish were removed from the San Mateo Creek Lagoon, and were treated as a threat to native fishes, particularly the Southern Tidewater Goby ( Eucyclogobius kristinae).

In Coyote Hills Marsh, Alameda, Procambarus clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata), reducing habitat for attached organisms and cover for prey species (Feminella and Resh 1989, cited by Cohen and Carlton 1995).

In Coyote Hills Marsh, Alameda, Procambarus clarkii reduced the abundance of Sago Pondweed ( Stukenia pectinata) (Feminella and Resh 1989, cited by Cohen and Carlton 1995).

Red Swamp Crayfish were removed from the San Mateo Creek Lagoon, and were treated as a threat to native fishes, particularly the Southern Tidewater Goby ( Eucyclogobius kristinae).

Burrowing by Procambarus clarkii is destructive to riverbanks, dikes and levees (Cohen and Carlton 1995).

Procambarus clarkii is reported to support commerical fisheries in the Delta, but may largely be taken incidentally for food and bait (Cohen and Carlton 1995).

Agriculture- Procambarus clarkii damages dikes and levees in rice fields (Riegel 1959; Cohen and Carlton 1995).

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First Non-native North American Tidal Record: 1955 First Non-native West Coast Tidal Record: 1959 First Non-native East/Gulf Coast Tidal Record: 1955 Procambarus clarkii, the Red Swamp Crayfish, is native to the Mississippi and Gulf of Mexico drainages from Florida, Mexico (the Rio Grande/Rio Bravo basin), and New Mexico north to Ohio and Illinois (Hobbs 1989; Campos et al.

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solutions are already being done to help this issue. 

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solutions are already being done to help this issue. 

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daily trapping, filling burrows, sound baiting, biological predication control and X-ray sterilization.

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Research reveals hope for managing invasive red swamp crayfish  | U.S. Fish & Wildlife Service

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Originally from the southeastern U.S., the red swamp crayfish has become an unwelcomed world traveler. They have drained wetlands in Europe and ruined rice crop in Asia. These invasive crayfish are highly aggressive and mobile. Here in the U.S., they are commonly spread by unsuspecting aquarium-hobbyists or biology teachers releasing the unwanted pet into their backyard ponds and rivers.

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possible solutions that could be done in the future. 

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possible solutions that could be done in the future. 

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Modification of size limits of predator fish species can be effective

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Originally from the southeastern U.S., the red swamp crayfish has become an unwelcomed world traveler. They have drained wetlands in Europe and ruined rice crop in Asia. These invasive crayfish are highly aggressive and mobile. Here in the U.S., they are commonly spread by unsuspecting aquarium-hobbyists or biology teachers releasing the unwanted pet into their backyard ponds and rivers. Despite the destructive nature of this species, we at the U.S. Fish and Wildlife Service haven't given up the fight.

As economies and ecosystems around the world struggle to contain this invasive, researchers funded by the Great Lakes Restoration Initiative in Michigan are leading the charge to develop practical eradication techniques.

In 2017, the red swamp crayfish initially found its first Michigan home in a hotel retention pond. The Michigan Department of Natural Resources spent three years trapping and removing more than 100,000 crayfish from the pond without ever reaching eradication.

Michigan has been trying to control booming populations of invasive red swamp crayfish for six years, and intensive efforts have only made a dent in their numbers. Thankfully, Michigan is no longer in the fight alone.

We are partnering with the Michigan Department of Natural Resources, Michigan State University, Auburn University and the U.S. Geological Survey to develop invasive crayfish control technologies. Serving as a hub for innovative eradication techniques, the initiative-funded partnership creates a direct research-to-management pathway.

If Michigan can learn to control invasive crayfish, innumerable ecosystems could be saved.

"They're just so prolific," said Kathleen Quebedeaux, an invasive crayfish biologist for the Michigan Department of Natural Resources. "They make so many eggs and are extremely hardy. It seems like they can live anywhere."

Quebedeaux works with her team on the ground to manage and monitor the invasive populations. She said that even though these crayfish are native to the southern U.S., they are surviving and even thriving here in the midwest.

Brian Roth, an associate professor at Michigan State University, works in the lab and in the field, searching for solutions to invasive crayfish issues. He said that this initiative-funded project is different from any other he has been a part of. A major barrier to successful invasives management is the extensive time it takes to learn new techniques and apply them. Roth stressed that a good idea in the lab doesn't always translate to the field.

"It is our rapid integration," Roth said, explaining what makes this program so unique. "I'm not talking 10 years here, I'm saying in the next year we'll find a way to scale a lab project up to the field."

Efforts to control red swamp crayfish have included daily trapping, filling burrows, sound baiting, biological predation control and X-ray sterilization, among other efforts. All of these approaches take a significant amount of time, money and scientific expertise. The team is excited to be developing techniques that bypass trapping and culling all together. They hope to find the most efficient and effective methods of management.

If red swamp crayfish numbers were to spiral out of control, their effects would be devastating to our waters. Red swamp crayfish are more aggressive than native crayfish, outcompeting them for food and space. The invasive is quick to disperse and has more stamina to travel. At infected retention ponds, the invaders have been found inside drainage pipes, meaning they have access to the greater watershed.

Furthermore, unlike native species, the invasive's burrowing habits are so intense they can collapse underground infrastructure as the sediments supporting piping shift and erode. Their burrows form unwanted drainage from wetlands. If left unchecked, these effects will ruin water quality, erase wetlands, collapse riverbanks and decrease water levels in beds of wild rice also know to the Anishinnaabeg people as manoomin.

"People are paying attention because it's not just Michigan, it's the entire Great Lakes basin," said Roth.

With the constant stream of invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species into our waterways - such as the recent invasion of signal crayfish into Minnesota - the need to control invasive crayfish populations and protect native species is greater than ever.

"This invasive," said Quebedeaux, "can be really harmful to all of our amazing resources in Michigan, things like water clarity which impact our native species abundance. If you like to get outdoors and see clean water, then you should care about this."

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Research reveals hope for managing invasive red swamp crayfish  | U.S. Fish & Wildlife Service

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Originally from the southeastern U.S., the red swamp crayfish has become an unwelcomed world traveler. They have drained wetlands in Europe and ruined rice crop in Asia. These invasive crayfish are highly aggressive and mobile. Here in the U.S., they are commonly spread by unsuspecting aquarium-hobbyists or biology teachers releasing the unwanted pet into their backyard ponds and rivers.

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picture of where red swamp Crayfish are.

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picture of where red swamp Crayfish are.

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Red Swamp Crayfish are invading the parts that are brown and were introduced to the parts that are red.

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This graph is showing how many red swamp Crayfish production per month and how much water discharge.

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how this project connects to things we have talked about in class?

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how this project connects to things we have talked about in class?

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The red swamp crayfish is a species that has successfully colonized a variety of freshwater ecosystems globally.

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Red Swamp Crayfish - Invasive Species Centre

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Red Swamp Crayfish (Procambarus clarkii) Adult red swamp crayfish. Photo: Rashid H. from eos.org French common name: écrevisses rouges des marais Order: Decapoda Family: Cambaridae Genus: Procambarus Species: clarkii Did you know? Female red swamp crayfish can carry up to 500 of their eggs underneath their tails, which enables them to spread quickly (Ontario Federation of Anglers and Hunters - OFAH, 2021).

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What are the ways middle schools can help with this issue?

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What are the ways middle schools can help with this issue?

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Clean watercraft of all aquatic plants and prohibited invasive species.

Drain all water by removing drain plugs and keeping them out during transport.

Dispose of unwanted bait in the trash. Dry docks, lifts, swim rafts and other equipment for at least 21 days before placing equipment into another water body.

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The red Swamp Crayfish is an alien invasive species: are animals and plants that are introduced accidentally or deliberately into a natural environment where they are not normally found.

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Both the European Commission and the Member States can propose additional species for inclusion on the Union list, according to Article 4(4) of the Regulation, including a risk assessment. All risk assessments are available here.

An overview of risk assessments under preparation is available here. A horizon scanning was commissioned in support of the selection process. It cannot be regarded as the list that the Commission will be proposing, nor to represent the opinion of the Commission.

Proposed risk assessments are first reviewed by the Scientific Forum. It provides an opinion on whether the risk assessments are robust and fit for purpose, according to an agreed procedure. While the Scientific Forum reviews these risk assessments, stakeholders are invited to submit additional evidence that could improve the risk assessments. The risk assessments currently under review by the Scientific Forum are available here.

Proposals for which the underpinning risk assessments receive a positive opinion from the Scientific Forum are forwarded to the IAS Committee. It examines the compliance of the proposed species with the criteria for listing (cf. Art 4(3) and 4(6) of the IAS Regulation). The approved risk assessments ready for the opinion of the IAS Committee are available here.

The Commission makes the draft proposal for an update of the Union list available for public feedback. Having considered this feedback, the Commission submits the final proposal for an update of the Union list to the IAS Committee. Any update of the Union list is subject to the positive opinion of the IAS Committee.

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Preventing and minimising the effects on invasive alien species on Europe's biodiversity.

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Red Swamp Crayfish are agricultural pest: Insects and mites that damage crops.

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Definition Insects and mites that damage crops, weeds that compete with field crops for nutrients and water, plants that choke irrigation channels or drainage systems, rodents that eat young plants and grain, and birds that eat seedlings or stored foodstuffs. Show source

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Red swamp crayfish are crustaceans: an animal with a hard shell and several pairs of legs, which usually lives in water.