People look at a 16-year-old critically endangered Hawksbill turtle after releasing it into the sea at the Sea Turtle Conservation Center east of Bangkok August 10, 2010.
Chaiwat Subprasom/Reuters
The report blamed one factor for this trend: humans. Pollution, deforestation, and habitat destruction due to farming and development have already "severely altered" 75% of all land and 40% of marine environments, it said.
But there may be hope. An international treaty was agreed on Saturday, after decades of negotiation. The High Seas Treaty aims to protect 30% of the Earth's oceans by 2030.
Here are the 14 extinct ocean animals (that we know of), and dozen others that are on the verge of extinction. And one that we thought was extinct but resurfaced recently.
Since the 1500s, 15 ocean animals have vanished from the world's oceans. Many were never photographed.
The Kiribati, or Christmas, Sandpiper (Prosobonia cancellata) went extinct in the 1800s.
Wikimedia Commons
There's urgency to protect wildlife.A 2017 study suggested the Earth is undergoing a process of "biological annihilation." As many as half of the total number of animal individuals that once shared the planet with us are already gone, it found.
The last Labrador duck ever seen was in Elmira, New York in 1878.
The sea duck generally wasn't hunted for food, but it's possible that European settlers pushed the animal out of its natural habitat.
Far fewer ocean species have gone extinct over the past 500 years than those on land — just 15 marine animals have gone extinct, compared to 514 terrestrial animal species, a 2015 study from the found. But that ratio could shift in the coming years.
The great auk disappeared in the mid-1800s. The flightless bird was not closely related to penguins, despite their similar appearance.
Humans once hunted the bird and harvested its eggs extensively. The great auk was even eaten by Neanderthals 100,000 years ago.
Other extinct ocean birds include the Saint Helena petrel and Pallas's cormorant.
The only marine fish to have gone extinct thus far is the New Zealand grayling. The Galapagos Damsel fish may also be extinct, but that has not yet been officially confirmed.
It lived and fed exclusively on one type of seagrass called eelgrass. But the population and distribution of eelgrass plummeted from disease in the 1930s, causing the limpet to die out.
Another species of sea snail native to China, called Littoraria flammea, also disappeared in the last 100 years or so.
The IUCN officially declared the Caribbean monk seal extinct in 2008, after the creature hadn't been seen for more than 50 years.
In 2007, experts thought they had located some remaining Japanese sea lions, but the creatures turned out to be California sea lions, which look very similar.
The carnivorous sea mink, which swam along the rocky coasts of New England and Nova Scotia, was hunted to extinction at the turn of the 20th century.
The American mink (Neovison vison) is a close relative of the now-extinct sea mink.
Wikimedia Commons
It was the largest type of mink, so hunters and fur traders pursued it with aplomb.
Stellar's sea cow, a manatee-like creature, was discovered in the frigid waters of Alaska's Bering Sea in 1741. Within 27 years, the animal had been hunted to extinction for its meat and hide.
One of the Stellar sea cow's living relatives, the dugong, swims near Marsa Alam, Egypt.
Julien Willem/Wikimedia Commons
As its name suggests, this sea cow was an herbivore, feeding mainly on kelp. It was covered in blubber like today's walruses to keep warm in the Arctic waters.
The dugong, a cousin of the Stellar's Sea cow, is now critically endangered.
An adult dugong swimming and feeding in the shallow water of Abu Dhabab in Marsa Alam, Red sea, Egypt
Sunphol Sorakul/Getty images.
The primary threats to the dugong are boat injuries, unintentional capture in fishing gear in East Africa, and poaching in New Caledonia, per an IUCN 2022 update.
Pollution from agriculture or oil exploitation is also leading to seagrass to become too scarce in both locations, per the IUCN
There are now only 250 mature individuals in East Africa and under 900 in New Caledonia.
In the past three decades, about 50% of coral reefs around the world have died.
A 2017 photo from NOAA shows bleached coral in Guam.
David Burdick/NOAA/AP
Oceans hit their warmest levels on record for the fourth consecutive year in 2022, according to a new report by two dozen scientists.
Higher water temperatures and acidification cause corals to expel the algae living in their tissues and turn white, a process known as coral bleaching.
Almost 33% of reef-forming corals are threatened with extinction, according to the recent UN report.
The beautiful iradescent abalone seashells are also under threat.
A Paua or abalone shell.
iStock / Getty Images Plus
Twenty of the world's 54 abalone species are now threatened with extinction, per the ICUN 2022 update.
Increasingly frequent and severe marine heatwaves are a critical danger for abalones. A 2011 heatwave killed 99% of Roe abalone in Western Australia, and the increased marine temperatures are making diseases spread more easily.
Overall, more than one-third of the world's marine mammals are threatened with extinction.
Duat Mai stands atop a dead whale at Ocean Beach in San Francisco, May 6, 2019.
Jeff Chiu/AP
According to the IUCN's Red List, 72 marine animal species are critically endangered, meaning they face an extremely high risk of extinction.
The short-nosed sea snake hadn't been seen since 2000. But it was spotted again in 2021, offering hope the species survived.
According to Australian Geographic, the species resides only in the Ashmore Reef and Hibernia Reefs off the coast of northwestern Australia.
The venomous snake prefers to munch on eels and fish and has been negatively impacted by warming ocean waters.
The snake had thought to have been extinct. But it was thankfully spotted once in 2021.
"The short-nosed sea snake was thought to be lost forever from Ashmore – so it truly is a remarkable find, the whole ship of researchers was squealing in excitement," said Karen Miller of the Australian Institute of Marine Science who made the discovery.
The most endangered marine mammal alive today is the vaquita, a tiny porpoise that swims in the warm waters of the Gulf of California.
Two vaquita swim in the Gulf of California off the western coast of Mexico.
NOAA/Wikimedia Commons
Vaquita means "little cow" in Spanish, and despite conservationists' best efforts to save the species, less than 30 of the animals remain today, according to the Marine Mammal Center.
Other critically endangered marine creatures include the Hawksbill turtle.
Hawksbill turtles are predominantly found in tropical oceans and coral reefs.
Hoffryan/Wikimedia Commons
An adult Hawksbill can weigh up to 150 pounds, according to the World Wildlife Fund. Named for its pointed beak, the Hawksbill turtle enjoys eating sea anemones, sponges, and jellyfish found around coral reefs. But poor reef health limits the turtles' access to food.
This endangered smalltooth sawfish looks like a shark, but it's actually a type of ray.
Named for its distinct nose, this creature was the first marine fish to receive federal protection as an endangered species under the Endangered Species Act in 2003, according to NOAA.
The Nassau grouper is an iconic Caribbean reef fish, but it's threatened by overfishing.
These fish are predators and are found near southern Florida, the Florida Keys, Bermuda, the Yucatan, and the Caribbean. The groupers swallow fish, crabs, and shrimp whole using suction created by their protruding mouths.
The starry sturgeon is also critically endangered. This fish frequents the Black, Azov, Caspian, and Aegean seas near central Europe and Asia.
Starry Sturgeon in the Pryvoz Market in Odessa, Ukraine.
Jewgienij Bal/Wikimedia Commons
Starry sturgeons can reach more than 7 feet in length and weigh 180 pounds. They, too, are threatened by overfishing. Fishermen harvest the species for its caviar.
The population of southern bluefin tuna has declined dramatically over the last five decades as well. Due to the high fat content of the fish's flesh, it's a popular delicacy.
A fisherman catches a southern bluefin tuna for tagging and release. Scientists tag the fish so they can learn more about their areas of distribution and behavior.
Marine Research, CSIRO/Wikimedia Commons
European eels are also approaching extinction due to overfishing.
The European eel is found throughout the Atlantic Ocean and the western Mediterranean.
Wikimedia Commons
In the Netherlands, eels are smoked and eaten with toast. Londoners eat jellied eels and enjoy eel stew. In Italy and Egypt, eels are often fried as a tasty treat.
In addition to overfishing, the construction of dams and decreasing water quality have caused declines in European eel populations, according to the European Commission.
Despite its clever camouflage tactics on the Atlantic ocean floor, the angelshark, or monkfish, is critically endangered, too.
Since 2010, it has been illegal to keep angelsharks caught in waters of the European Union.
In addition to all the species listed here, there are more than 60 other critically endangered marine animals in the oceans today, according to the IUCN. All of these creatures have been negatively impacted by dying coral reefs, rising ocean temperatures, and pollution.
The High Seas Treaty aims to protect more of the ocean.
People walk past United Nations headquarters in New York on March 3, 2023
Daniel SLIM / AFP/Getty Images
Two-thirds of the world's oceans are in international waters, and up to now, only 1% of those were protected.
That means that most of the marine wildlife was at risk from climate change, fishing, and collisions with boats.
The treaty aims to achieve the protection of 30% of the ocean by 2030.
A previous version of this article was published on May 6, 2019 and was updated to reflect the High Seas Treaty agreement. Aylin Woodward contributed to the previous version of this article.
.jpg#/media/File:Aipysurus_apraefrontalis_specimen_(SAMA_R68142).jpg){kind=link}
.jpg){kind=link}