Olive Ridley Turtles Mass Nesting in Odisha

Check here facts about Olive Ridley Turtles, the smallest and most abundant sea turtles, known for their unique mass nesting behavior called 'arribada.' Learn about their habitat, lifecycle, and conservation status.

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Context: Nearly 7 lakh Olive Ridley turtles nested at the Rushikulya rookery in Odisha’s Ganjam district between February 16 and February 25, 2025. This marks a strong comeback after the absence of mass nesting in 2024.

About Olive Ridley Turtles

They are the 2nd smallest and most abundant of all sea turtles found in the world.
- Smallest sea turtle in the world: Kemp’s ridley sea turtle.
- Largest Sea turtle: Leatherback Turtle
It gets its name from the olive-green colouration of its carapace (shell).
Distribution: Mainly found in warm waters of the Pacific, Atlantic and Indian Oceans.

Features

They are known for unique arribadas (synchronised mass nestings), where thousands of females come together on the same beach to lay eggs.
Females nest every year and produce up to 100 eggs.
Males and females grow to the same size, but females have a slightly more rounded carapace.
They are omnivorous, meaning they feed on both plants and animals.

Major Sites in India

Gahirmatha Marine Sanctuary: Located in the Kendrapara district of Odisha, this is the world’s largest nesting site for olive ridley turtles.
Rushikulya Beach: Located in the Ganjam district of Odisha. The mouth of the Rushikulya River is the 2nd largest nesting site for olive ridley turtles in India.
Velas Beach, Versova Beach & Tarkli Beach (Maharashtra)

Conservation Status

IUCN Red List: Vulnerable
Wildlife Protection Act, 1972: Schedule 1
CITES: Appendix I

Arribada – The Unique Mass Nesting Phenomenon

Arribada (Spanish for ‘arrival’) refers to the synchronized mass nesting of thousands of female turtles.
Unique to the genus Lepidochelys, which includes Olive Ridley and Kemp’s Ridley turtles.
Over 600,000 females emerge in 5-7 days to lay eggs during arribada.

Nesting Process

Turtles dig conical nests (1.5 feet deep) using their hind flippers.
Eggs take about 50 days to hatch.

Global Arribada Sites

Largest: Odisha, India – Rushikulya & Gahirmatha rookeries.
Other major sites: Mexico and Costa Rica.

Why is Odisha’s Coast Ideal for Mass Nesting?

Favourable weather: Warm sandy beaches, undisturbed coastal ecosystem.
Rushikulya River Mouth (North side) is preferred due to:
- Mild beach slope and medium sand percentage.
- Low salinity of nearshore waters.
- Lower wind speeds and moderate waves before nesting.
- Higher wind speeds during nesting help turtles reach the beach.