India: Mission to save the dugong to help marine ecosystems

The government of India's southern Tamil Nadu state announced the country's first-ever conservation reserve for the dugong last year. 

Situated in the Palk Bay area of the Gulf of Mannar, the reserve not only aims to protect the marine mammal against poaching and harmful fishing practices, but may also help to shield the coastline from the worst impacts of climate change.

Dugongs, the only herbivorous sea mammal in the world, are classified as vulnerable by the International Union for Conservation of Nature (IUCN).

Their decline may have wider consequences, however, and present a threat to the fragile ecosystem that depends on them. "Dugongs feed exclusively on seagrass, and the two have a highly mutually dependent relationship," said Rukmini Shekar, a former project fellow at the Wildlife Institute of India.

"The dugong keeps the seagrass cropped," she said, which helps to regenerate the grass and prevent algae growth. "And it also helps the dugong, because they prefer foods that are rich in nitrogen and low in fibre."

Seagrass, a marine plant which grows in shallow waters, is hugely beneficial to coastlines. It produces oxygen and cleans coastal waters, and protects against rising sea levels and natural disasters by absorbing wave energy.

What's the link between seagrass and climate change?

Research also suggests that seagrass could play a major role in mitigating climate change, capturing carbon from the atmosphere 35 times faster than tropical rainforests. 

Despite this, seagrass meadows globally are being lost at a rate of around 7% each year, mostly due to human activity and warmer ocean temperatures. 

By focusing on dugong conservation, the new reserve in Tamil Nadu may present a solution, said Shekar, by facilitating the regeneration of seagrass, as well as the ecosystem that the habitat supports.

The Gulf of Mannar is a haven of marine biodiversity, harboring several species of sea turtle, fish, molluscs and crustaceans.

By protecting dugongs, "all the species, which share the same habitat also get a better environment to grow," said Shekhar Kumar Niraj, who was the conservator of forests in the Tamil Nadu government when the reserve was formally announced last year. "It's a kind of umbrella effect."

The habitat also acts as a juvenile nursery bed for many commercially important fish, supporting the livelihoods of local traditional fishermen in the Palk Bay area. Recently however, high market demand has brought commercial fishing trawlers to the area, threatening both the fragile ecosystem and the livelihoods which depend on it.

Trawler nets have weights on the bottom and floats on top to maximize catch areas, which can result in overfishing and damage to the seagrass beds, said Shekar. "Once they pull, it literally brings up everything." 

Overfishing and poaching pose problems

Murugesan, a local fisherman, said that one species of fish, which he used to catch, has been completely wiped out because of trawling. "You don't get any of that fish now because there's less seagrass."

Fishing can also be harmful to dugongs if they become accidentally entangled in the nets. Dugongs have to surface for air much more regularly than other marine mammals, pointed out Shekar, coming up every three to eight minutes.

"When they get entangled in nets, then they can't come up to breathe. So even a span of about 20 to 30 minutes is fatal," she said.

Poaching is a problem too. Dugong meat is considered a delicacy, which means that sometimes fishermen choose to sell the dugongs that get trapped in their nets rather than release them — despite this being illegal.

In early 2020, Murugesan's son was out on fishing when a dugong got entangled in his net.

"Usually people bring it [to shore], because you can sell it," he said. "But I kept saying that you should let it go. Because it's against the law."

Murugesan said that dugong meat can sell for 300-400 rupees ($3.50 to $4.80) per kilogram, meaning that a fully grown dugong can bring in profits that are over 100 times what a fisherman would usually make in a day. 

Shekar's colleagues at the Wildlife Institute of India are working with locals to raise awareness of the laws against poaching, as well as trying to increase their engagement with conservation efforts. They offer financial incentives to fishermen who release trapped dugongs back into the water.

Murugesan's son ultimately released the dugong and received compensation of 10,000 rupees, which was split evenly among the crew members.

Engaging the community to take part in conservation

The new reserve aims to further increase community engagement with conservation efforts, positioning local fishermen as stakeholders through a "collaborative management system," said Niraj.

It will also promote traditional methods of small-scale fishing, ensuring that "fishing remains conservation friendly and sustainable."

"There will be more awareness, they will be more skilled in doing their activities, even while they are also able to spare their efforts for the conservation," he underlined.

Niraj hopes that the lessons learnt here will be transferable, providing a model for other coastal conservation programs across India, and helping to contribute towards the country's global climate pledges — such as the Global Biodiversity Framework,  whose goal is to protect at least 30% of the world's coastlines through effective conservation and management.

"If we are able to successfully [implement the goals of the reserve] and sustain it for the long term, it will make a tremendous contribution to climate mitigation narratives," Niraj conculded.

Edited by: Srinivas Mazumdaru