Kurma mela: the science of the mass nesting of Olive Ridley turtles, Pg20

Olive Ridley turtles have shown mass nesting (arribada) at Rushikulya beach, Odisha, a rare and remarkable natural event.

These turtles return to the same nesting beaches with high precision, guided by environmental cues and earth’s geomagnetic fields.

Despite this resilience, their global population has declined 30–50% since 1960, per IUCN Red List estimates.

Odisha is a global nesting hotspot, also hosting Gahirmatha and Devi river mouth beaches.

Detailed Insights:

Arribada is a synchronized, large-scale nesting event — turtles return to the beach where they hatched.

Phenomenon involves environmental imprinting, geomagnetic cues, and ocean current memory, termed philopatry.

Eggs and hatchlings are vulnerable to predators, erosion, and human interference.

Disrupted nesting leads to confusion and decline in return rates, weakening population genetics and survival.

Rising tourist intrusion—night photography, sand removal, crowding—poses ethical and ecological concerns.

Some hatchlings emerge during day, increasing mortality due to predators and heat exposure.

Conservationists now push for buffer zones, awareness, and visitor regulation to protect the cycle.

Key Concepts:

Philopatry: The tendency of an organism to return to or stay in its birthplace for reproduction.

Arribada: A mass nesting event unique to Olive Ridley turtles.

Geomagnetic Imprinting: Turtles use Earth's magnetic field as a navigation tool to find their birthplace.

Significance:

Symbolizes how fragile ecological memory and instinct guide species survival.

Demonstrates the delicate balance between conservation and tourism.

Raises ethical concerns about human disruption of sensitive biological events.

Reinforces the need for science-based policies and public sensitisation in biodiversity hotspots.

Mains Mock Question:

Mass nesting of Olive Ridley turtles is both a natural wonder and a conservation challenge. Discuss the scientific basis of their philopatry and the threats posed by increasing human intervention.