Urgent action needed to conserve the endangered Irrawaddy dolphin

© naturepl.com / Roland Seitre / WWF

Sporting a bulging forehead, a round face and a flexible neck (rare among dolphins), the Irrawaddy dolphin gets its name from the Irrawaddy River in Myanmar. But despite its name, it is not solely a river dolphin. This endangered oceanic dolphin is euryhaline, a rare type of marine life that has adapted to survive in fresh and saltwater environments. Preferring to stick close to shore, this species lives in freshwater and coastal areas throughout Southeast Asia.  

Due to its affinity to coastal habitats, this dolphin has a long history with communities and is sacred in many cultures. In Myanmar, there are many accounts of this species helping fishers catch fish by herding fish into their nets. But as modern fishing techniques evolve, this form of fishing, called cooperative fishing, is rarely practiced today. 

“This coastal living puts this species in significant danger. Pollution, habitat degradation, climate change, underwater noise pollution, and damming of rivers are all considered serious threats to the Irrawaddy dolphin,” says Samantha Ambie, Marine Mammal Conservation Officer, WWF Malaysia, Marine Programme. “However, the largest threat, by far, is bycatch, the incidental capture of non-target species such as whales, dolphins, marine turtles and seabirds.”

Collateral damage

Wherever there is fishing there is bycatch. Modern fishing gear is strong and nearly undetectable, making it highly effective for catching fish. However, this indestructible netting does not discriminate and traps anything in its path. A staggering amount of marine life is hauled up and thrown overboard dead or dying. 

© WWF Cambodia

Estimates indicate that more than 300,000 whales, dolphins and porpoises die from bycatch yearly, making this the single largest cause of mortality for small cetaceans. Bycatch of cetaceans occurs in all kinds of fishing operations, from large industrial to localised artisanal fisheries. It also happens with most types of fishing gear, including driftnets, gillnets and entangling nets.

© Shutterstock / Mohamed Abdulraheen / WWF-Peru - Ghost Gear

Moreover, every year, 640,000 tonnes of fishing gear is abandoned, lost or discarded in the ocean. This fishing gear, commonly called ghost gear, accounts for a minimum of 10 per cent of all marine litter. Ghost gear can persist for up to 600 years before eventually disintegrating into microplastics. 

The impacts of bycatch on the Irrawaddy dolphin

Due to its coastal habitat and tendency to feed near fisheries, the Irrawaddy dolphin is heavily impacted by bycatch. Large numbers of these dolphins are killed by entanglement in gillnets. The dolphins are also threatened by illegal fishing activities including electrofishing.

This species has a low reproductive rate. Therefore, even if a seemingly small number of dolphins is killed by incidental catch it can have a serious impact on the population.

The Irrawaddy dolphin is a keystone species, an indicator of a healthy habitat and stable food chain. This dolphin plays an important role in the top-down control of coastal and oceanic ecosystem structure and function, helping recycle nutrients and enhance primary productivity. 

Reversing the decline of Irrawaddy dolphins through collaboration

WWF-Malaysia, the Sarawak Forestry Corporation (SFC) and the Universiti Malaysia Sarawak (UNIMAS) are collaborating on a project to help determine population size for the Irrawaddy dolphin and other marine mammal species, as well as raise awareness with fishers to reduce incidental catch.

The project has been ongoing for two years. Current results include positive support from fishers and relevant authorities, as well as confirmation from fishers onboard observation surveys that bycatch is a threat to Irrawaddy dolphins and other marine mammals in Rajang-Belawai-Paloh. Additionally, fishers have started to show involvement in marine mammal conservation, including reporting incidental catch to SFC and participating in outreach activities.

“The presence of dolphins can be an indicator of fish abundance to the fishers. Dolphins are important for the future. If dolphins are extinct in the future, it can affect our livelihood as a fisher,” say Osman Bin Tinggal, a local fisher, and Rostinawati Binti Abdul Said, a housewife and community member. “We are supporting the conservation efforts being done, to secure the dolphin population in the Rajang-Belawai-Paloh area.”

“Several examples of mitigation measures that would help reduce incidental catch of Irrawaddy dolphins and other marine mammals include time-area closures, the use of acoustic deterrent devices (like pingers), light emitting diodes (LEDs), which have been implemented in other parts of the world and were successful in reducing incidental catch of dolphins from fishing gear,” says Samantha Ambie. “By reducing the threats these dolphins face, our hope is that this project can successfully maintain population size, and that the dolphins can live in harmony with local communities.”

“Our plan is to start exploring these mitigation measures during the next phase of the project,” adds Samantha. “It’s going to take collaboration between WWF-Malaysia, our partners, the government, and the fishers committee to implement these measures effectively and help reverse the decline of Irrawaddy dolphins in this region.”