The importance of sea turtles to marine ecosystem

Context:

• The role of sea turtle ranges from maintaining productive coral reef ecosystems to transporting essential nutrients from the oceans to beaches and coastal dunes.
• But as turtle populations in general decline, so does their ability to play a vital role in maintaining the health of the world’s oceans.

What are sea turtles?

• Sea turtles(superfamily Chelonioidea), sometimes called marine turtles are reptiles of the order
• The majority of a sea turtle’s body is protected by its shell.
• The turtle’s shell is divided into two sections: carapace (the dorsal portion) and plastron (the ventral portion).
• The shell is made up of smaller plates called

How many types of sea turtles are found in the world’s ocean and India in particular?

Seven species of sea turtles swim in the world’s oceans:

• Flatback (Natator depressus),
• Green (Chelonia mydas),
• Hawksbill (Eretmochelys imbricata),
• Kemp’s ridley (Lepidochelys kempii),
• Leatherback (Dermochelys coriacea),
• Loggerhead (Caretta caretta) and
• Olive ridley (Lepidochelys olivacea)

There are five species in Indian waters:

• Leatherback (Dermochelys coriacea),
• Loggerhead (Caretta caretta),
• Green (Chelonia mydas),
• Hawksbill (Eretmochelys imbricata), and
• Olive Ridley(Lepidochelys olivacea).

What is the importance of sea turtles?

Healthy fish stocks:

• Sea turtles, especially the Leatherback, keep Jellyfish under control, thereby helping to maintain healthy fish stocks in the oceans.

Provides home for numerous species of marine life:

• The Green turtle feeds on sea grass beds and by cropping the grass provide a nursery for numerous species of fish, shellfish and crustaceans.
• Without constant grazing, seagrass beds become overgrown and obstruct currents, shade the bottom, begin to decompose and provide suitable habitat for the growth of slime molds.
• The Hawksbill feeds on sponges in the reef ecosystem and opens up crevices for other marine life to live in.
• By removing sponges from reefs, hawksbills allow other species, such as coral, to colonize and grow.

Provides nutrients and energy to coastal areas:

• Turtles are also transporters of nutrients and energy to coastal areas.
• Sea turtle eggs directly and indirectly affect the vegetation, species distribution and stability of sandy shorelines.
• By supplying a concentrated source of high-quality nutrients, sea turtles improve their nesting beaches.

Benefit Ocean Floor Ecosystems:

• Loggerheads are equipped with powerful jaws to feed on hard-shelled prey, such as crustaceans.
• This allows them to reduce the shells of their prey into fragments that are either discarded on site or further away in the form of feces.
• By breaking up the shells while foraging, loggerheads increase the rate at which the shells disintegrate and increase the rate of nutrient recycling in benthic or ocean bottom ecosystems.

What are the threats for sea turtles?

• Every year, thousands of sea turtles are accidentally captured, injured or killed by mechanised boats, trawl nets and gill nets operated and used by comercial fishermen.
• They can also sustain internal injuries from fishing hooks or suffer serious external injuries after becoming entangled in nets.
• Each year, environmentalists record a high number of dead turtles washing up ashore.
• This heavy toll, of injuries and deaths, occurs when turtles begin migrating to their nesting grounds on beaches and in fishing areas that are their feeding grounds.
• Also Bycatch, which is the name given to ocean animals that are unintentionally caught by fishing gear is another threat for these sea turtles.

What are the measures taken to conserve sea turtles in India?

• In India, though sea turtles are protected under the Indian Wildlife Protection Act of 1972, under the Schedule I Part II.
• Scientists are now working on programmes such as new fishing nets and gear that reduce the amount of bycatch while fishing.
• Growing public interest in bycatch reduction programmes is motivated by factors such as an appreciation for endangered species and concern for maintaining marine biodiversity.
• Under current regulations, mechanised trawl boats are not allowed to operate within 8 km of the shore in Andhra Pradesh, 5.5 km in Tamil Nadu and 5 km in Odisha.
• Similarly, nets set for ray fish are banned under the law during the season.
• In the U.S., all trawl shrimp fishing vessels need to be equipped with turtle excluder devices or TEDs, which are two-dimensional net inserts with large escape openings for turtles.
• Likewise in India, trawlers meant for shrimp fishing are required by law to be fitted with TEDs.
• If used correctly, TEDs have been found to reduce turtle captures by 90%.

Suggestions:

• These bans need to be enforced at all levels of fishing and monitored by the respective Fisheries departments, marine police and the Indian Coast Guard.
• All areas where fishing boats land need to be monitored.
• All trawl boats should be fitted with a vessel monitoring system that must be kept on at all times.
• This will provide a simple system of monitoring by the Coast Guard.
• These small but meaningful measures will help the sea turtles that are our marine heritage has another chance at survival.