Our eco-system is comprised of interdependent animals and plants which constitute a complex web of life. This variety of life on earth, the biodiversity that features numerous interactions among the species, is most vital to the existence of our planet and, particularly, of the humanity. Thus, indeed the extinction of a single species may affect the whole biological system pertaining to life and living things. Unfortunately, the improperinterventions of human beings in nature are pushing several of the species in the ecosystem to the brink of extinction. The unprecedented unnatural extinction of these species has not only theendangered functioning of the ecosystem but also affected the ecological issues to alarge extent.
From unknown creatures to Charismatic megafauna, these disappearances in the ecosystem happen frequently. On land, animals like Orangutan, Black Rhinos, Amur Leopard and Giant Pandas are some of the most critically endangeredspecies in the world. Similarly, many marine species including marine mammals, sea turtles and salmonidsare also on the edge of extinction as climate change andoverfishing become amajor threat to their existence.According to the International Union for Conservation of Nature (IUCN), hundreds of marine species across the world come under the categories of endangered and critically endangered species. IUCN, at regular intervals, determines the status of species considering the probability of their extinction, from least concern to extinct. Some of these majorly endangered and recognizable marine species are named here.
1. Hawksbill Turtle (Eretmochelys imbricate)
Found in the tropical regions of all the world’s oceans, gulfs and seas- mostlyin coral reefs, the Hawksbill Turtle’s population has been estimated to have declined by 80% over the last century. Known to be a subject of heavy trafficking in the tourist trade in tropical regions for its meat and shells, these turtles are being killed mercilessly for quite a period of time.The colourful shells of the Hawksbill Turtle, with beautiful patterns, make them a valuableitem in the market, often sold as “tortoiseshell.”
Even though in many countries harvesting of its eggs is banned, the practice could not be ceased completely. The declination of its population has also resulted due to the degradation of coral reef species which the Hawksbill Turtle primarily feed on.According to marine conservatives, this family of theturtle is the living representatives of reptiles that have existed in our oceans for the past hundred million years and these turtles are vital for the existence of seagrass beds and coral reefs.
2. Vaquita(Phoeocna sinus)
An inhabitant of the shallow, murky waters off the shore of the Baja Peninsula in Mexico, Vaquita is the world’s smallest and critically endangered cetacean. This rare marine mammal in the world is on the brink of extinction only after ahalf-century of its first sighting. Features of Vaquita include the dark rings around their eyes, lips with dark patches and a thin line from mouth to dorsal fins.
Extensive use of gill-netting for fishing in the Gulf of California has endangered this marine species, resulting in a gradual drop in population since the1940s.The gill-netting operation may have been ceased to exist in 1970, but the population fall persists for as much as 15% every year. According to reports, there is only a dozen of this marine mammal left in the world since the percentage of decline in their population was as much as 90% since 2011.
3. Blue Whale (Balaenopteramusculus)
The largest living mammal on earth, the blue whale belongs to the baleen whales and features more than 100 feet in length and around 200 tonnes in weight. There are at least three subspecies of Blue whale and these could be found migrating from both poles in the oceans around the world. Sits on top of the food chain, whales have a significant role in maintaining a healthy marine environment.
Unfortunately, the excessive commercial hunting has resulted in the decrease of its population drastically and now has posed a threat to its mere existence even though an international ban was constituted in 1966. According to IUCN’s 2016 estimate, the global population of the Blue Whale is 10,000–25,000.
4. Kemp’s Ridley sea turtle (Lepidochelys kempii)
The Kemp’s Ridley sea turtle, also known as the Atlantic Ridley sea turtle, is a rarest and smallest sea turtle and is endangered to a severe degree. Primarily found in the Gulf of Mexico, the Kemp’s Ridley sea turtle often migrate to the Atlantic Ocean only to come back to lay eggs. This group turtlehas a unique way of nesting habits. The female turtles arrive in large numbers- a procession called Arribadas- in a single beach to lay eggs.
Unfortunately, the conditions such as loss of habitat, marine pollution and entanglement in fishing nets etc. have resulted in the huge decline of the population of the Kemp’s Ridley sea turtle. Thus, harvesting of eggs have been made illegal and research projects of incubating and hatching the eggs in temperature-controlled rooms have been undertaken to save this endangered marine species.
5. Steller Sea Lion (Eumetopiasjubatus)
Evidently the largest member of the Otariid family and the fourth largest of all seal species, this eared seal could be located in the cold coastal waters of the North Pacific. Also known as the northern sea lion, the species is named after Georg Wilhelm Steller, a naturalist who first discovered them in 1741.
The high risk of predation by Killer Whales and fishing and harvest by native Alaskans and Canadians for meat, oil, hides and other by-products make this marine life vulnerable to endanger.According to reports, its population has declined by more than 60% due to both natural and human threats since the1960s. However, the eastern Steller sea lion was omitted from the U.S. Endangered Species List in 2013 after their increasing population in the recent years.
6. Hammerhead Shark (Sphyrna mokarran)
Traced in the tropical regions of the oceans around the world, the Hammerhead shark belongs to the family Sphyrnidae and was given the name because of its “hammer” shaped head. The Hammerhead sharks typically have 0.9 to 6.0 m length and up to 580 kg weight. Known as aggressive hunters, these sharks are feed on smaller fish, squid crustaceans and octopuses, while there are reports of unprovoked attacks on humans by the shark.
These migratory sharks are subjected to being victimized for its fin. Even the process itself is horrifying as the sharks are caught by fishermen, dragged on board and is cut off their fins while they are still breathing.The remaining carcass is thrown into the water and eventually, it bleeds to death. Albeit there is a ban imposed upon shark finning in many countries, the result has been abortive as the demand and high price paid for it in the Asian market drives the illegal harvest system, endangering these marine species’ survival.
7. Fin whale (Balaenopteraphysalus)
Also known as common rorqual, Fin whale is the second-largest mammal on the planet after Blue Whale. With a maximum length of 25.9 meters, the Fin Whale has an estimated weight of about 114 tonnes. Like all the other whales in our oceans, the Fin Whale is also a victim of hunting for a long period of time. According to estimates, the global population of Fin Whale ranges from below 100,000 to around 119,000.
Humpback Whale, another rorqual species, has also been listed as an endangered marine species. Before the introduction of whaling moratorium in 1966, these species were hunted to extinction for its fur and flesh for meat, while the population dropped by 90%. Currently, around 2,500 Humpback Whale is believed to surviving in the world.
8. Hector’s Dolphin (Cephalorhynchushectori)
Found off the coast of New Zealand, Hector’s Dolphins are the smallest dolphins in the world and the prominent dolphin in the genus Cephalorhynchus. Mostly sighted around the South Island, the world’s rarest dolphins’ features include black markings on the face, stocky bodies and creamy white throat and belly. One group of Hector’s Dolphin will be comprised of two to eight members.
Unfortunately, there is asignificant decline in their population as trawl fisheries and bottom-set gillnets cause the death of these species. Most number of deaths happens in the fishing nets. One of the two sub-species of Hector’s Dolphin, Maui’s dolphin, is considered to be a most endangered one. According to the survey conducted by the New Zealand Department of Conservation in 2010-11, the estimated population of these dolphins is 55.
9. Hawaiian Monk Seal (Monachusschauinslandi)
A native of the Northwestern Hawaiian Islands, Hawaiian Monk Seal is one of the earless seals who live in the warm beaches,unlike other seals. This endangered marine mammal is one of the two remaining in this species-monk seal- along with the Mediterranean monk seal, while third species from this family, the Caribbean monk seal, has already disappeared from the planet. According to the recent research, there are only around 1,400 Hawaiian Monk Seal remaining on the Islands now. The existence of these seals is threatened by commercial hunting for meat, oil and skin, attack from predators including tiger sharks, marine debris and entanglement in fishing nets.
10. Green sea turtle (Cheloniamydas)
One of the largest sea turtles, Green Sea Turtle is a herbivore and can be found in the tropical and subtropical seas. The Green Sea Turtle’s name comes from the colour of the fat that found underneath its carapace. Like many other turtle varieties, Green Sea Turtles also migrate from its hatching beaches to feeding grounds.
Since these sea turtles are always been a popular food item, the hunt for turtles and their eggs is threatening their lives. The loss of sandy beaches, marine population and careless fishing methods also have added to the decline of their population.
Apart from these mammals and turtles, salmonids and seabirds also have confronted the menace of endangered ocean species. The Maritime Mammal Protection Act (MMPA-1972) and The Endangered Species Act (ESA-1973) have contributed so far to salvage this ocean life but it requires adequate awareness about these issues and the transcendence of the human behaviour in accordance to that, which can inevitably make a difference for these ocean endangered species.