#316: Dugong, the sea cow!
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• Appearance & Behavior:
Herbivorous marine mammals, often called "sea cows"
• Diet & Feeding:
Seagrass (Cymodocea, Halophila, Thalassia, Halodule); they digest cellulose, wearing down and regrowing teeth rapidly.
• Habitat
Andaman-Nicobar, Gulf of Mannar, Gulf of Kutch, Palk Bay etc.
• Lifespan & Social Structure
Can live up to 70 yrs, typically solitary in India (large herds seen in Australia)
• Slow Reproduction
Min 9-10 age before reproduction, max population growth 5% per year
World Dugong Day
Significance: Celebrated annually on May 28, it raises awareness about dugong conservation and their role in marine ecosystems.
Conservation Status and Population Decline
• IUCN Listing: Dugongs are classified as "vulnerable" globally on the IUCN Red List and "regionally endangered" in India, with numbers dwindling to around 200 individuals.
• Population Trend: Once widespread in Indian waters, their population and geographic range have significantly declined due to habitat loss and human activities.
Threats to Dugongs
• Habitat Degradation: Seagrass meadows, critical for dugongs, are rapidly degrading due to coastal development, agricultural runoff, industrial pollution, and climate change (rising sea temperatures, ocean acidification, extreme weather).
• Fishing Practices: Mechanized boats, gillnets, and trawl nets cause accidental entanglement, leading to drowning; traditional non-mechanized fishing has been replaced, exacerbating habitat destruction.
• Human Activities: Increased boat traffic in key habitats (Gulf of Mannar, Palk Bay, Gulf of Kutch) leads to collisions; pollution (mercury, organochlorines) accumulates in dugong tissues, affecting health.
• Illegal Hunting: Despite Schedule I protection under the Wildlife Protection Act, 1972, poaching persists in remote areas of the Andaman and Nicobar Islands.
Vulnerability Factors
• Slow Reproduction: Dugongs reproduce slowly, with low birth rates and long intervals, making populations highly vulnerable to disturbances.
• Habitat Dependency: Require vast, undisturbed seagrass meadows, which are increasingly under threat, limiting their ability to thrive.
Way to the Future
• Dugong Behavior: Dugongs are shy, avoiding human interaction, leading to low awareness among coastal/fishing communities and limited focus from conservation groups.
• International Commitments: India, a party to the Convention on the Conservation of Migratory Species since 1983, signed the Memorandum of Understanding on Dugong Conservation and Habitat Management in 2008.
• Conservation Milestone: In 2022, India established its first dugong conservation reserve in Palk Bay, Tamil Nadu (448.3 sq. km), with 122.5 sq. km of intact seagrass beds, a key habitat.
• Collaborative Efforts: The reserve results from long-term monitoring by the OMCAR Foundation, Wildlife Institute of India, and Tamil Nadu Forest Department, focusing on dugong conservation and seagrass restoration.
• Ecological Role & Urgency: Dugongs, described as "gardeners of the sea," nurture seagrass meadows; their survival hinges on urgent action against pollution, coastal development, and habitat neglect, per Ms. Hatkar.
Conservation Strategies for Dugongs
• Seagrass Habitat Protection:
Rigorous mapping and monitoring of seagrass meadows to identify priority conservation areas like the Gulf of Mannar Biosphere Reserve.
Restrict activities damaging seagrass; promote community-led stewardship involving local fishers to monitor and restore seagrass habitats.
• Regulating Fishing Practices:
Ban harmful practices like gill nets and bottom trawling in dugong habitats to prevent entanglement.
Promote sustainable, non-destructive fishing techniques traditionally used by fisherfolk.
• Community Involvement & Ecotourism:
- Develop dugong-friendly ecotourism with local youth as eco-guides to monitor populations, raise awareness, and empower communities.
- Conduct awareness campaigns in coastal villages on dugongs’ ecological importance; train locals to report sightings/strandings for rescue operations.