A dugong sand sculpture at Danushkodi seaside to mark World Setting Day in June 2022.
Waving meadows of emerald grasses half as a portly form drifts via the shallow waters. Like a blimp led astray, the creature makes use of its entrance flippers to paddle gently because it nibbles on the seagrass that makes its house. Silt stirs from the shallow seafloor, coral reefs reveal themselves in a riot of colors, with shoals of fish scurrying out of the way in which, and a whole ecosystem comes into view.
Meet the dugong — the farmer of the ocean.
Could 28 is widely known yearly as World Dugong Day. Dugongs (Dugong dugon) are the one herbivorous mammals present in India’s marine ecosystems. This mild large — referred to as the ocean cow however resembling a cross between a seal and a whale — is distributed via the Indo-Pacific area. As a consequence of their dependence on seagrass beds for habitat and meals, dugongs are restricted to shallow waters, the place they spend the day feeding on seagrasses of the genera Cymodocea, Halophila, Thalassia, and Halodule. They root on the base of shorter seagrass species, consuming rhizomes, stems, and leaves, thus clouding the shallow waters. That is how they earned their epitaph. (Additionally see the addendum.)
Seagrass is low in vitamins, so dugongs feed extensively all through the day to fulfill their each day necessities. They will devour 20-30 tonnes of seagrass per day, crushing leaves and stems in opposition to their horned tooth earlier than swallowing. Not like different marine mammals, the way in which they eat permits dugongs to digest cellulose, though the method wears down their tooth rapidly. Because of this, dugongs quickly regrow tooth in a number of iterations all through their lives.
Not like manatees, their shut kin, dugongs are extra strictly marine, preferring waters a number of metres deep. They’re discovered alongside the Indian shoreline, primarily inhabiting heat waters across the Andaman and Nicobar Islands, the Gulf of Mannar, Palk Bay, and the Gulf of Kutch. The dugong is a long-lived species, in a position to stay as much as 70 years.
Dugongs are additionally typically solitary or present in small mother-calf pairs. Researchers have sometimes noticed small teams, however massive herds — as are frequent in Australian waters — are uncommon in India.
People attain reproductive maturity after solely 9 or ten years and may give delivery at intervals of round three to 5 years. As a consequence of its sluggish reproductive cycle, prolonged time to maturity, and rare calving, a dugong inhabitants’s most potential progress fee is estimated to be nearly 5% per 12 months.
Threatened waters
However for his or her unassuming nature, dugongs are listed as being ‘vulnerable’ on the IUCN Pink Record for Threatened Species. The threats they face worldwide embrace quickly declining populations and the continued degradation of their seagrass habitats. In India, they’re categorised as ‘regionally endangered’. As soon as widespread in Indian waters, their numbers have dwindled to an estimated 200 people, with each their inhabitants dimension and geographic vary persevering with to say no.
Based on analysis by impartial marine researcher Prachi Hatkar, coastal areas round India are more and more below strain from increasing residential, leisure, and agricultural actions. As extra folks stake declare to those areas, the danger of air pollution rises. Air pollution also can have an effect on them instantly, with research exhibiting the buildup of mercury and organochlorine compounds of their muscle tissues.
As a result of dugongs reproduce slowly and require huge, undisturbed seagrass meadows to thrive, their populations are extremely susceptible to human disturbances. Seagrass meadows, their major habitats, are being misplaced at an alarming fee. Main threats stem from altering fishing strategies, which threaten the meadows. Fishers as soon as relied on non-mechanised boats to fish in shallow waters, together with seagrass habitats. However with the appearance of contemporary fishing applied sciences, these conventional boats have steadily given approach to mechanised ones.
The development of ports, dredging, and land reclamation for industries and tourism have additionally wreaked havoc on these delicate ecosystems, and air pollution from agricultural runoff, sewage, and industrial effluents have degraded water high quality, affecting seagrass well being.
The ever-present risk of local weather change, perceptible in rising sea temperatures, ocean acidification, and excessive climate occasions like cyclones, additionally impacts seagrass ecosystems, lowering the provision of meals in addition to secure breeding habitats for dugongs.
One other main risk to dugong populations in Indian waters is unintentional entanglement in fishing gear, particularly gillnets and trawl nets. Dugongs are air-breathing mammals that should floor commonly. However as soon as entangled, they usually drown earlier than fishers can launch them. Many of those deaths go unreported, additional complicating conservation efforts.
Elevated human motion and exercise in dugong habitats and extra boat visitors within the Gulf of Mannar, Palk Bay, and the Gulf of Kachchh — all instantly threaten the species. Dugongs additionally usually relaxation close to the floor, making them susceptible to collisions with fast-moving boats, resulting in accidents or fatalities.
One more risk is against the law looking. Whereas dugongs are a Schedule I species in India, having fun with the best degree of safety granted by regulation, poaching nonetheless happens, particularly within the distant areas of the Andaman and Nicobar Islands.
Technique to the long run
Not like manatees, dugongs are shy creatures, preferring to keep away from interacting with people when potential. This creates a common lack of information in regards to the species, even amongst coastal and fishing communities, in addition to much less consideration from the bigger conservation neighborhood. India has been celebration to the Conference on the Conservation of Migratory Species of Wild Animals since 1983 and has additionally been a signatory to the Conference’s Memorandum of Understanding on Dugong Conservation and Habitat Administration throughout their vary since 2008.
In 2022, the Authorities of India formally introduced the creation of the nation’s first dugong conservation reserve, spanning 448.3 sq. km within the coastal waters of Palk Bay, Tamil Nadu. Current research have indicated that this bay is the final stronghold for these mild herbivores in Indian waters, and the proposed reserve space has round 122.5 sq. km of intact seagrass beds, making certain habitat and meals for the dugong inhabitants.
This transfer, to guard the species at a nationwide degree, stems from long-term monitoring and analysis by the OMCAR Basis (an NGO), the Wildlife Institute of India, and the Tamil Nadu Forest Division: they’ve been working to enhance dugong conservation and seagrass restoration for greater than a decade. Their efforts can go a good distance in making certain the survival of dugongs and their delicate lives.
“Dugongs are gentle giants and act as gardeners of the sea, quietly shaping our oceans by nurturing seagrass meadows,” Ms. Hatkar stated. “But their survival now depends on ours — on how urgently we act to protect their fading habitats from pollution, coastal development, and neglect.”
Serving to dugong conservation
An vital step folks can take is to guard and restore seagrass habitats. To take action, we’d like rigorous mapping and monitoring of current seagrass meadows to establish extra precedence conservation areas, very like the Gulf of Mannar Biosphere Reserve. Actions that injury seagrass must be restricted and community-led seagrass stewardship, together with involving native fishers to observe and restore seagrass, can go a good distance in sustaining the dugongs’ habitat. Regulating dangerous fishing practices, similar to banning gill nets and backside trawling, in identified dugong habitats can even assist forestall unintentional entanglement.
We additionally want to advertise non-destructive, sustainable fishing methods that fisherfolk have used up to now. Different livelihood choices similar to dugong-friendly ecotourism utilizing native youth as eco-guides can fulfil the twin position of monitoring dugong populations whereas elevating consciousness of their habitats and behavior, all whereas empowering native communities.
Growing consciousness and neighborhood involvement have all the time been vital elements of dugong conservation. Many conservation practitioners are conducting consciousness campaigns in coastal villages in regards to the ecological significance of dugongs, and plenty of native communities and fishers are skilled to report dugong sightings or strandings, facilitating rescue operations when wanted.
One other vital aspect is strengthening analysis. Researchers want extra assist, each monetary and institutional, for long-term research of dugong populations, behaviours, genetics, and threats. Growing citizen science programmes and utilizing the standard ecological information of native communities will add one other dimension to current analysis. Moreover, advances in tagging and drone know-how could be mobilised to trace dugong actions and establish important habitats.
Addendum: why seagrass issues
Seagrass is an underwater flowering plant, to not be confused with seaweed. Labeled as wetland ecosystems, seagrass meadows stabilise the seafloor, assist fisheries, seize carbon, and shelter marine life. Wholesome seagrass is important for dugongs and marine life similar to turtles and fish. A 2022 research by the Nationwide Centre for Sustainable Coastal Administration documented 516.59 sq. km of seagrass habitat in India. This interprets to a carbon dioxide sequestration potential of as much as 434.9 tonnes per sq. km every year.
India’s most in depth seagrass meadows happen alongside the Gulf of Mannar and Palk Bay, off the coast of Tamil Nadu, and collectively assist greater than 13 species of seagrass — the best range within the Indian Ocean. The Andaman and Nicobar Islands additionally assist wealthy seagrass beds and related biodiversity. Whereas seagrass is current within the shallow reefs of the Lakshadweep Islands and alongside the coast of Kachchh, they’re patchy regardless of being ecologically vital. In Kachchh specifically, port actions and air pollution threaten these coastal wetlands. The coast of Andhra Pradesh and Odisha additionally helps minor seagrass beds alongside estuaries, however these habitats should not in depth or appropriate for dugong populations as we speak.
Priya Ranganathan is a doctoral pupil and researcher on the Ashoka Belief for Analysis in Ecology and the Setting (ATREE), Bengaluru.
Revealed – Could 28, 2025 05:30 am IST
