All of these oceans are in the marine biome.The ocean climate varies from warm to cold depending on the area. 

 

Coral:  Coral reefs are home to microscopic algae called zooxanthellae that live in the crevices of the reef. Coral exist in shallow waters, which means the algae living in them can be very close to sunlight. And sunlight is an important ingredient in photosynthesis, the process in which plants make their own food.  Coral reefs adapt by symbiotic relationships. 

Coral

Sea Cabbage: They are long, leathery, and large in size. They are also referred as the Devils Apron or The Sea Colander. They can be found in the Atlantic Ocean and the Northern Pacific Ocean.

Seaweed: Certain seaweeds are tough and leathery, this protects them from being torn or dried out by the sun.

Algae: Several different types of algae attach to rocks in order to not float away. 
Kelp: The kelp is a very large sea weed so its root system or the holdfasts are very strong so it can attach itself to the sea floor when large storms come through the area.

https://youtu.be/GE-lAftuQgc
Sharks-the dorsal fins,
Swordfish-long swords on nose , 

Blue whales-more metabolic activity to adapt to cool temperatures
https://www.telegraph.co.uk/news/earth/earthnews/6219970/Blue-whales-forced-to-make-more-noise-to-compete-with-ships.html
Seals-taper tails
https://en.wikipedia.org/wiki/Grey_seal
Octopus-color changing

Cuttlefish-blending in with predators
 https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwi0ypraoZreAhXH6lMKHT24AOsQjB16BAgBEAQ&url=https%3A%2F%2Fes.123rf.com%2Fphoto_19242354_primer-plano-de-una-sepia-sepia-officinalis-com%25C3%25BAn.html&psig=AOvVaw2eftUrSpIVItkcCs_gcyPZ&ust=1540304711083708

https://www.hawaiimagazine.com/content/5-things-about-hawaiian-monk-seal-you-need-know
When was it considered endangered: The Hawaiian monk seal was officially designated as an endangered species on November 23, 1976, and is now protected by the Endangered Species Act and the Marine Mammal Protection Act. It is illegal to kill, capture or harass a Hawaiian monk seal. 
The best estimate of the current total Hawaiian monk seal population is 1,400 seals. 

Population Estimate: The sub-population of seals in the NWHI has generally suffered from annual declines for decades due to several natural and potentially human-related causes, some of which are not, as-yet, fully understood. Inappropriate human-seal interaction can negatively impact pupping behavior and pup survival, can disrupt needed monk seal rest cycles, can lead to conditioning seals to human presence posing a danger to both seals and humans, and can expose seals to attacks from pets and their related injuries, disease and death. The Hawaiian monk seal is susceptible to several diseases that could lead to widespread seal deaths.  For example, an outbreak of Phocine distemper virus (PDV) in 1988 caused the death of over 10,000 harbor seals in northern Europe.
Affects to biome: Seals are top predators. They eat fish, squid, and crustaceans, including some of the species that the fishermen catch. ... Marine ecosystems are complex, with seals and other top predators playing important roles in maintaining an ecological balance.
https://sites.google.com/site/hawaiianmonkseal0/habitat
- Outreach programs: Due to other government priorities, federal and state agencies charged with the support of Hawaiian monk seal field response have insufficient funding to mount all of the work and activity needed.
-Where? The majority of the Hawaiian monk seal population can be found around the Northwest Hawaiian Islands but a small and growing population lives around the main Hawaiian Islands. These seals spend two-thirds of their time at sea.
_https://www.youtube.com/watch?v=vK3GsLWbwNo