Plight of Ocean Species Shows Need to Preserve Earth's Variety of Life

Krill are the life force of the Southern Ocean, serving as prey for numerous species of penguins, seals, and whales. Other Antarctic predators, such as leopard seals and orcas, eat the animals that consume krill.

Bigeye tuna, found in the warm waters of the Atlantic and Pacific oceans, are formidable predators that can swim deeply and grow to over 400 pounds. In the Atlantic, bigeye are overfished, a clear signal that fisheries managers must act to protect them.

Deep-water black coral, Leiopathes annosa, thought to be the world’s oldest living organism at about 4,265 years old, is found exclusively within the waters of the Hawaiian Islands at depths of 305 to 488 meters (1,000 to 1,600 feet).

This blue plate coral off Jarvis Island in Australia’s Coral Sea is protected in a marine park. Studies show that large, highly protected reserves give species a better chance of surviving numerous threats, including climate change.

The bumphead parrotfish is listed as vulnerable on the International Union for Conservation of Nature Red List of Threatened Species. In 1994, lawmakers in the island nation of Palau enacted the Marine Protection Act, which includes a moratorium on fishing for the species in its waters.

The butterfly fish is one of at least 142 species found only in the waters of Easter Island. The waters around this remote special territory of Chile are protected in a reserve that allows locals to continue fishing using an ancient artisanal technique.

Scientists discovered this ghost-like octopod in the Papahānaumokuākea Marine National Monument in Hawaii in 2016. The monument is one of the world’s largest marine protected areas.

The dugong, listed as vulnerable on the IUCN Red List, lives in the waters off the Pacific island nation of New Caledonia and the Kimberley region of West Australia. These “sea cows” graze on grasses in shallow coastal areas.

The South Georgia and South Sandwich Islands, which sit more than 1,700 kilometers (1,050 miles) from the tip of South America, near the intersection of the South Atlantic and Southern oceans, are home to 54 percent of all southern elephant seals. Protection of this area is vital because it is a living laboratory for studying the impacts of climate change—teeming with life, changing dynamically due to rapidly warming waters, and relatively undisturbed by human activity.

Fur seals thrive on the rocky shores alongside Bernardo O’Higgins National Park in the Aysen region of southern Patagonia in Chile. They live in colonies on rocky coasts, where they are protected by shade and can easily slip into the water during hot and dry weather.

This critically endangered tortoise species is found only in the Galapagos Islands, some 600 miles off the coast of Ecuador. While the tortoise is protected under Ecuadorian law, illegal fishing of sharks and other species is a chronic problem in this region, one that the government is working to end.

The giant spiny lobster lives in the waters of Walters Shoals, off the southern tip of Madagascar. This isolated species was first discovered in 2005, and can weigh about 9 pounds.

Guitarfish and wedgefish are large bottom-dwelling sharks with strong ray-like features—note pectoral fins joining at the head. They bury themselves in the sand and use their snout and pebble-like teeth to catch passing crustaceans.

Hawaii’s Papahānaumokuākea Marine National Monument is a critical habitat for this species, which is one of the most endangered marine mammals in the world, according to the Marine Mammal Center. Threats include entanglement in marine debris, habitat loss, and human disturbances, for example on beaches where the seals come to rest, give birth, and nurse their pups.

Humpback whales migrate from the cool north to the warm south to calve, wintering in Revillagigedo, a marine protected area in the Pacific waters of Mexico. They also use the protected waters of southern Patagonia in Chile to raise their young.

The Papahānaumokuākea Marine National Monument protects one of the largest groupings of seabirds in the world—an estimated 14 million birds from 22 species. Wisdom, the Laysan albatross pictured in the foreground, is at least 65 years old and is thought to be the world’s oldest bird. She returned to her birthplace on Midway Atoll, which is in the monument, in 2016 to successfully hatch a chick.

Leatherback sea turtles can live nearly half a century, weigh up to 2,000 pounds, and grow up to 7 feet in length. These turtles are highly migratory, often traveling thousands of miles across the high seas to breed and feed.

Marine otters (Lontra felina)—which live off the coasts of Argentina, Chile, and Peru—are endangered, with population declines driven by habitat loss, pollution, poaching, and hunting. This otter lives only in marine habitats, favoring rocky shores and caves, as well as large algae communities that attract an abundance of prey.

Also known as a humphead, this reef fish is listed as endangered by the IUCN, primarily due to fishing pressure. Around the island nation of Palau, however, this and all other marine species are safeguarded under a 2015 law that designated around 80 percent of the country’s waters as a fully protected marine reserve.

Pacific bluefin tuna is one of the most depleted tuna species on the planet—fished down more than 97 percent from its historic levels. These fish can swim up to 25 mph and migrate great distances, often from Japanese waters to those of the United States and Mexico. Numerous governments agreed to a plan last year to help the species rebuild, but it remains threatened due to decades of overfishing.

Shortfin makos have been clocked at speeds up to 45 mph, which helps when they are chasing their favorite meal, tuna. These sharks thrive in warm or cold water, and are found in almost every ocean. They’re also prized for their meat and fins and are thus threatened by overfishing.

First sighted off Australia in 2005, the snubfin was the first new dolphin species discovered in more than 50 years. “Snubbies,” as they are known, live off the West Australian coast, in places including Roebuck Bay in the Great Kimberley Marine Park.

Toothfish are critical to the Southern Ocean food web, in part because they’re the top fish predator in the East Antarctic, a region that has been proposed for marine protections since 2011. Scientists know little about these fish, other than the fact that they can grow up to two meters in length and produce anti-freeze proteins to prevent their blood from crystallizing in frigid waters.

Endemic to the Antarctic, Weddell seals live farther south than any other mammal. These skilled predators can dive for more than an hour and reach depths below 1,900 feet (580 meters). While Weddells are protected under the Antarctic Treaty and the Convention for the Conservation of Antarctic Seals, their food sources, such as Antarctic toothfish and krill, are under increasing pressure from industrial fishing.

Whale sharks are the largest fish in the ocean, with some weighing over 10 tons and reaching lengths of 40 feet. These gentle giants swim in tropical and temperate waters, and have been identified by the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as a high priority for conservation. In 2017, CMS members voted to prohibit the catch of these endangered species.