Sea turtles are among the most endangered animals on earth but why are sea turtles endangered? This is done to the many threats they face. Most of these threats are created by humans.
Threats are varied and numerous but the main threats include bycatch in marine fisheries, loss of nesting habitat due to beach development, presence of artificial light sources and magnetic interference that can alter the behavior of nesting females and hatchlings, the over-harvesting of the eggs, the presence of marine debris, climate change, disease, and oil spills.
Out of the even marine turtles, only the flatback isn’t classified as threatened by the IUCN Red List of endangered species. This is only because there isn’t enough information/data on the flatback to properly classify it. The flatback is considered endangered in Australia.
Table of Contents
|1.3. Habitat Loss for Development|
|1.4. Marine Debris|
|1.5. Oil Pollution|
|1.6. Climate Change|
|2. Threats per Species|
|2.1. Green Sea Turtles|
|2.2. Loggerhead Sea Turtles|
|2.3. Leatherback Sea Turtles|
|2.4. Hawksbill Sea Turtles|
|2.5. Olive Ridley Sea Turtles|
|2.6. Kemp’s Ridley Sea Turtles|
|2.7. Flatback Sea Turtles|
Reasons Why Sea Turtles Are Endangered
Bycatch In Marine Fisheries
One of the main reasons why sea turtles are endangered is bycatch in marine fisheries. Turtles are usually bycatch because they are not the marine animal that fishers want to catch.
Unfortunately, because turtles breathe air, they die when trapped in fishing equipment. A turtle tracked in a fishing net can die in a matter of minutes.
When stressed turtles use up the oxygen in their lungs pretty quickly. Fishing techniques that result in turtles being trapped and dying include drift netting, long lining, shrimp trawling, and dynamite fishing with the long lining being known to be the major cause of accidental sea turtle bycatch deaths.
In the Bay of Bengal alone, almost 1000 sea turtles died as a result of a bycatch in marine fisheries in a time span of just a few months.
One way to reduce sea turtle bycatch is by using turtle excluder devices (TED). While these devices don’t eliminate bycatch altogether, they significantly reduce the occurrence.
Turtle excluder devices (TED) have their disadvantages such as the difficulty to enforce TED usage as they reduce the catch of trawlers.
Overharvesting of Turtle Eggs and Turtles for Their Meat
One of the main reasons why sea turtles are endangered is the harvesting of sea turtles for food/ this includes both the eggs and the meat for consumption. The main issue is that sea turtle is a staple part of many coastal communities’ foods. As such the eggs are collected in large quantities to be sold on the market.
In many fishing communities around the world, the collection of turtle eggs is used to supplement household incomes. The eggs can be in high demand in cities close to beaches where these turtles nest.
In many of these communities, it is almost impossible to stop people from consuming turtle eggs and meat as it is an important part of the culinary culture of the people. This is particularly true of communities found on the Caribbean coast in places such as Nicaragua where an estimated 35,000 sea turtles are killed yearly.
An approach taken by the Nicaraguan government is to work with locals to reduce the among of turtle eggs and turtle meat consumed. Locals in fishing communities are allowed to take a limited number of eggs in return for helping to protect nests from overexploitation. This strategy seems to have reduced the number of eggs collected in fishing communities on Caribbean beaches.
On the beaches of Chacocente and La Flor in Nicaragua, the Cacibolca Foundation helps to protect nests from exploitation by collecting turtle eggs and nesting them in a nursery that is protected. Once the eggs hatch, the hatchlings are returned to the ocean.
In places such as the United States and Mexico, “Don’t Eat Sea Turtle” campaigns are launched to reduce the consumption of turtle meat and eggs.
Habitat Degradation and Beach Development
Large portions of the nesting habitats are being divided all over the world. With this nesting habitats are very much at risk.
With the degradation of the habitat because of beachfront developments, the turtles have fewer locations to nest. Turtles may still come to a nest, but the presence of artificial lights, sounds, and noise poses a huge problem for nesting females.
Nesting females usually nest during the night. The light of buildings can confuse the turtle. Nesting females have been known to move towards traffic instead of the sea.
It isn’t only nesting females that are at risk, hatchlings are also at risk as they mostly leave the nests at night. Hatchlings find the ocean by moving to the brightest horizon.
All the lights from beachfront developments can disorient the hatchlings. If the hatchlings do not make it to the sea they usually end up dying.
Because of these deaths caused by habitat degradation in particular beach development, measures have to be taken. In places such as the east coast of Florida, the nesting habitats have been protected by fences.
Conservationists and marine biologists working at sea turtle conservations such as Gumbo Limbo Nature Center, Miami-Dade County Sea Turtle Conservation Program, and World Wide Fund for Nature relocate lost hatchlings and even nurture lost hatchlings to health to be released into the ocean.
In some locations, lighting restrictions are placed on beaches where sea turtles nest. Some of these restriction includes the use of sea turtle-safe lighting such as amber and red LED lamps as these lights are not visible to sea turtles.
Presence of Marine Debris
Marine debris is a huge contributor to the endangered nature of sea turtles. Debris such as plastics are sometimes confused for jellyfish.
Turtles can choke on these plastics and end up dying. Discarded fishing nets are also troublesome as turtles and other marine animals can become trapped in them.
Why are sea turtles endangered? The use of plastic is one of the main reasons. Recycling can significantly reduce the negative effect however many people aren’t recycling.
Also littering nesting beaches is also a major contributor to the endangered nature of sea turtles. About 80 percent of beach litter is plastic.
Even hatchlings are at risk as they can get caught in the plastic litter which can stop them from making it to the ocean. Trapped on the beach, these turtles will starve to death or die from the heat of the sun.
Okatuc can be confused with jellyfish or even algae which the turtle eats. This can become logged in the intestines of the reptile and lead to internal bleeding which can end up killing the turtle.
The presence of plastic in the stomach of sea turtles seems to be growing. According to research done by a laboratory of Exeter and Plymouth Marine, researchers found plastic in the stomach of every turtle they tested. This included a sample size of 102 turtles.
Oil spills are another factor that contributes to the endangerment of sea turtles. The oil poisons a turtle when it enters its digestive tract.
The chemicals from oil ingested by the turtle are thought to be passed on to hatchlings from affected nesting females. The presence of these chemicals makes it difficult for the hatchlings to thrive or even survive.
Climate change is a potential factor that can threaten the existence of sea turtles. How is this so? The sex of sea turtles is determined by the temperature of the sand within which the nesting females lay the eggs.
If the temperature overall is higher, more females will be produced than males. If the ratio of females to males is too high, it will reduce the future fertility of the wild populations. Studies show that more females are hatchlings than males.
Also, the rising sea levels across the world due to global warming can make it difficult for females to recognize nesting beaches.
Threats Faced by Turtle Species
Threats Faced By Green Turtles
Green turtles (Chelonia mydas) can be found all over the world and mostly occur in tropical waters and subtropical waters to a much lesser extent. They nest in over 80 countries and inhabit the Pacific, Atlantic, and Indian Oceans as well as the Mediterranean Sea.
Threats that green turtles face according to the IUCN Red List include overharvesting of the eggs and meat; the degradation of nesting beaches and foraging habitats; and incidental capture in marine fisheries including long-ling, dynamite fishing, shrimp trawling, and drift netting.
The green turtle (Chelonia mydas) is defined as Endangered on the IUCN Red List with the last assessment being in 2004.
Threats Faced By Loggerheads
Loggerheads (Caretta caretta) can be found mainly in temperate and subtropical waters of the Atlantic, Indian, and Pacific Oceans, and the Mediterranean Sea.
Threats faced by loggerheads include the incidental capture of specimens in fishing equipment meant to catch other marine species, the utilization of the eggs and meat/shells for human consumption, coastal developments, pollution & pathogens such as fibropapilloma virus, and climate change which will likely impact future populations.
Threats Faced By Leatherbacks
Leatherbacks (Dermochelys coriacea) can be found all around the world but are known to nest in the tropics.
These giants are known to forage in tropical, subtropical, temperate, and even sub-polar latitudes. They are the only turtles that are capable of foraging in subarctic waters.
The species face several threats. These include fisheries bycatch; the overcollection of eggs for human consumption; beachfront developments such as beach modification, dredging, and constructions; pollution including light pollution, debris, and oil spills; pervasive pathogens like fibropapilloma which causes the growth of external tumors; and global warming.
Threats Faced By Hawksbills
Hawksbills (Eretmochelys imbricata) are critically endangered according to the IUCN Red List. The species was last assessed in 2008.
The species is endemic to the tropical waters of the Pacific, Indian, and Atlantic Oceans. They can even be found in the subtropic waters of these same oceans. The species is known to nest in more than 70 countries.
According to IUCN Red List, threats that the species face include egg collection; slaughter for meat; degradation/destruction of nesting beaches and foraging habitats including coral reefs and tropical coastlines; the ingestion of marine debris such as plastic; entanglement in marine debris such as fishing equipment including gillnets and fishing hooks; and oil pollution which is known to impact hawksbills more than other sea turtle species.
Threats Faced By Olive Ridley
The olive ridley (Lepidochelys olivacea) can be found in the tropic waters of the Atlantic, Pacific, and Indian oceans. They however cannot be found in the Gulf of Mexico. They are also found in some subtropical latitudes.
The species face a large number of threats. Targeted exploitation which includes egg harvesting and the direct taking of subadults and adults is one of the main threats that the species face.
Other threats include bycatch in fisheries; habitat impacts; diseases such as fibropapilloma; and predation by dogs, wild pigs, and even beetle larvae on incubating eggs. The olive ridley is considered vulnerable on the IUCN Red List.
Threats Faced By Kemp’s Ridley
The geographic range of Kemp’s ridley (Lepidochelys kempii) is quite limited. The turtle can be found in the Gulf of Mexico; the Atlantic coasts of Madeira, the Azores, Bermuda, Europe, Canada, and the United States; and the Mediterranean sea.
The species only nest in the Gulf of Mexico. The largest nesting habitat is close to Playa de Rancho Nuevo in Mexico. The nesting habitats are found from Veracruz in Mexico to Texas in the United States.
According to the ‘Kemp’s Ridley Sea Turtle 5-year Review’ by U.S. Fish and Wildlife Service & National Marine Fisheries Service and the Bi-National Recovery Plan for the Kemp’s Ridley Sea Turtle by National Marine Fisheries Service the following are the main threats to the species – toxins, natural catastrophes such as hurricanes; oil spills; cold stunning; predation; climate change; dredging; illegal harvest; industrial plant entrainment and intake; fisheries bycatch including in drift & sink gillnet, demersal longline, pelagic longline, pot, bottom trawls, and top & midwater trawls; and vehicular accidents including boat strikes.
Kemp’s ridley is listed as critically endangered on the IUCN Red List.
Threats Faced By Flatbacks
The flatback (Natator depressus) is endemic to Australia. While there is little information on the threats it faces, they are most likely the same as other turtles.
Frequently Asked Questions
Why are sea turtles endangered?
Sea turtles are endangered because they face a large number of threats. These threats include bycatch in marine fisheries, loss of nesting habitat due to beach development, presence of artificial light sources and magnetic interference that can alter the behavior of nesting females and hatchlings, the overharvesting of the eggs, the presence of marine debris, climate change, disease, and oil spills.
Which turtles are critically endangered?
Both the hawksbill (Eretmochelys imbricata) and the Kemp’s ridley (Lepidochelys kempii) are considered to be critically endangered.
Which sea turtles are considered endangered?
The turtle considered to be endangered is the green turtle (Chelonia mydas). Of course, critically endangered species are also endangered so both the hawksbill (Eretmochelys imbricata) and the Kemp’s ridley (Lepidochelys kempii) are also endangered.
Which sea turtles are considered vulnerable?
The leatherback (Dermochelys coriacea) is classified as vulnerable. Vulnerable means that the species is vulnerable to becoming endangered.
The flatback status on the IUCN Red List is listed as data deficient as enough data haven’t been collected to properly assess the species. The species is considered Vulnerable under the Australian Commonwealth’s Endangered Species.
Sea turtles are among the most endangered animals. All sea turtle species are classified as threatened in one way or another.
Only the flatback isn’t classified as threatened by the IUCN Red List of endangered species. This species is still considered vulnerable in Australia.
Out of the other species, the hawksbill (Eretmochelys imbricata) and the Kemp’s ridley (Lepidochelys kempii) are classified as critically endangered; the loggerhead (Caretta caretta), the olive’s ridley (Lepidochelys olivacea), and the leatherback (Dermochelys coriacea) are classified as vulnerable; and the green turtle (Chelonia mydas) is classified as endangered on the IUCN Red List.
The main reasons why sea turtles are endangered include the overharvesting of eggs, degradation of their natural habitats, and bycatch in marine fisheries.