Olive Ridley Turtle Population Trends in Odisha

Rising global temperatures are impacting the Olive Ridley turtle population in Odisha’s Rushikulya rookery. A recent report by the Dakshin Foundation marks that increased temperatures are leading to a higher number of female hatchlings. This trend raises concerns about the long-term viability of the population. The report, titled “Monitoring Sea Turtles in India 2008–2024,” reveals findings about hatchling sex ratios and the overall health of turtle populations in India.

Rushikulya Rookery Overview

Rushikulya is one of India’s largest mass nesting sites for Olive Ridley turtles. It is located at the mouth of the Rushikulya River in Ganjam district, Odisha. The rookery plays important role in hatchling recruitment. Research has been conducted here for over 15 years, focusing on nest temperatures and hatchling sex ratios.

Hatchling Sex Ratios

The Dakshin Foundation’s research indicates that the average sex ratio of hatchlings from mass nesting events, or arribadas, is approximately 71% female. Some years exhibit extreme female-biased ratios due to elevated nest temperatures. However, there are instances of male-biased ratios in certain years. Overall, the sex ratios at Rushikulya are not as skewed as those found in some global populations.

Long-Term Monitoring

The report is the culmination of 16 years of research, involving community engagement and conservation efforts. Collaborations with the Indian Institute of Science and various state forest departments have been integral to the study. Monitoring sea turtles is complex due to their long lifespan and migratory nature, with population changes occurring over extended periods.

Population Stability and Concerns

Kartik Shanker from IISc and Dakshin Foundation states that the Olive Ridley population appears stable or increasing. However, the absence of arribadas in some years raises questions. Offshore monitoring suggests large numbers of turtles are present, yet their nesting behaviour remains inconsistent. Ongoing threats to coastal and oceanic habitats necessitate vigilance.

Other Turtle Species

The research also examined leatherback turtles in the Andaman Islands. Nesting has increased on Little Andaman Island since the 2004 Indian Ocean Tsunami. Telemetry studies revealed that these turtles travel extensively, reaching locations as far as Madagascar and Western Australia. Green turtles in Lakshadweep are also expanding in number, causing ecological shifts in seagrass meadows.

Conservation Challenges

Marine turtle populations face numerous threats. Coastal development, pollution, and climate change pose risks. In India, the overlap of turtle foraging and breeding sites with fishing grounds impacts local livelihoods. The study marks the importance of involving local communities in conservation efforts. Collaboration among fishers, researchers, and policymakers is essential for sustainable practices that benefit marine biodiversity and human well-being.

Questions for UPSC:

1. Critically analyse the impact of climate change on marine biodiversity.
2. What are the key threats to marine turtle populations? How can these be mitigated?
3. Point out the significance of community involvement in wildlife conservation efforts.
4. Estimate the ecological implications of increasing green turtle populations in Lakshadweep.

Answer Hints:

1. Critically analyse the impact of climate change on marine biodiversity.

1. Climate change leads to rising sea temperatures, affecting breeding and feeding patterns of marine species.
2. Altered ocean currents and weather patterns can disrupt migration routes and habitat availability.
3. Increased ocean acidification impacts coral reefs, which are vital for marine ecosystems.
4. Species may face extinction due to inability to adapt to rapid environmental changes.
5. Changes in species distribution can lead to imbalances in marine ecosystems and food webs.

2. What are the key threats to marine turtle populations? How can these be mitigated?

1. Coastal development leads to habitat loss for nesting and foraging.
2. Pollution, including plastic waste, harms turtles through ingestion and entanglement.
3. Climate change affects nesting sites and hatchling sex ratios due to temperature fluctuations.
4. Bycatch in fishing gear poses threat to turtle populations.
5. Mitigation strategies include creating protected areas, sustainable fishing practices, and community education on conservation.

3. Point out the significance of community involvement in wildlife conservation efforts.

1. Local communities possess valuable knowledge about local ecosystems and species behavior.
2. Involvement encourages a sense of ownership and responsibility towards conservation efforts.
3. Collaboration with fishers and researchers can lead to sustainable practices that benefit both biodiversity and livelihoods.
4. Community engagement can enhance monitoring and enforcement of conservation regulations.
5. Successful conservation initiatives often rely on the active participation of local stakeholders.

4. Estimate the ecological implications of increasing green turtle populations in Lakshadweep.

1. Increased green turtle populations may lead to overgrazing of seagrass meadows, affecting their health and biodiversity.
2. Changes in seagrass dynamics can impact other marine species that rely on these habitats for food and shelter.
3. Higher turtle populations may influence local fisheries by altering the balance of species in the ecosystem.
4. Ecological shifts could affect nutrient cycling and overall marine ecosystem health.
5. Monitoring and adaptive management strategies are essential to balance turtle populations and ecosystem health.