The Irrawaddy dolphin needs our help

With their petite size ranging from 2 to 2.8 meters (6 to 9 feet), Irrawaddy dolphins (Orcaella brevirostris) possess an endearing resemblance to baby beluga whales. What sets these shy and endangered dolphins apart is their super cute and expressively charming faces. In this post, we highlight some fascinating facts about these endangered marine creatures.

A small geographical range

Irrawaddy dolphins live in coastal areas in South and Southeast Asia. They also live in three rivers: the Ayeyarwady (Myanmar), the Mahakam (Indonesian Borneo), and the Mekong River. The Mekong Irrawaddy dolphins’ habitat consists of only 190 km (118 miles) of the Mekong River, northeast of Cambodia, and southwest of Laos. Their habitat has been greatly reduced after the construction of multiple dams on the Mekong River.

Shy yet photogenic

Irrawaddy dolphins are known for their reserved nature, often evading boats and displaying a shy demeanor. They possess the ability to submerge underwater, holding their breath for up to 12 minutes, although their typical diving periods are brief, usually under 1 minute. In contrast to more lively and acrobatic dolphin species like spinner dolphins, Irrawaddy dolphins typically refrain from leaping above the water or showcasing elaborate behaviors. Their swimming speed is not particularly high, with a recorded maximum of around 25 km/h (15 mph).

Other reports mentioned that Irrawaddy dolphins get bullied by humpback dolphins in the Mekong river. They usually flee as soon as they get close to the humpbacks… It seems that Irrawaddy dolphins are the underdogs of their environments. Yet, being shy does not mean they cannot look cute! Look at this face …

Cooperative fishing with humans

Burma’s (Myanmar) Irrawaddy dolphins collaborate with fishermen to catch fish. Experienced fishermen “call” the dolphins, drumming a wooden stick on their boats. The dolphins soon show up and help herd the fish inside the nets. Fish is getting rarer and rarer in this part of the river and fishermen may not afford to give part of their prize back to the dolphins. Yet, experts think that the dolphins can collect some fish within the nets and this might be the reason why they keep helping fishermen.

This relationship is fragile and has suffered from shameless fishing activities. Some local fishermen, despite the regulations, resort to electroshock fishing, depleting the river’s remaining resources. Some fishermen even electrocuted a couple of trusting Irrawaddy dolphins in the past. As a result, the angered dolphins are sometimes hesitant to collaborate with fishermen.

An endangered species

In 2017, the IUCN declared the Irrawaddy dolphin as endangered, signaling a critical status for the species. The population, particularly in the extensively studied Mekong River area, has plummeted to a mere 92 individuals, compared to 200 two decades ago, posing a severe risk of extinction.

The main threats to their survival include bycatch in nylon gillnets, overfishing that depletes the rivers of their fish, boat traffic causing stress and collisions, dams that limit the size and quality of their habitat, and chemical pollution from pesticides, plastics, and heavy metals. Addressing these multifaceted challenges is imperative to secure the future of the endangered Irrawaddy dolphin population.

Hope remains

With joint effort from the local authorities, residents, and NGOs like WWF, the Irrawaddy dolphin Mekong population has been stable since 2010. More calves are being born while fewer dolphins die annually. This is great news for these beautiful creatures. The implementation of ecotourism has not only benefited the dolphins but also provided support to local fishermen. We still lack information from the populations in the other rivers and from coastal areas. Maybe this could be a fantastic opportunity if you are an aspiring marine mammalogist … The Irrawaddy dolphins need you!

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We hope you liked our post and learned a thing or two about Irrawaddy dolphins. Do not hesitate to share it to raise awareness of these mostly unknown dolphins. We would also like to warmly thank Anupam Koley for allowing us to use their photos on this post

Sources:

• IUCN Status
• WWF
• Fishermen collaboration
• International Whaling Commission
• Humpback dolphins and Irrawaddy dolphins interaction: Sinha, R.K., 2004. The Irrawaddy dolphins Orcaella brevirostris of Chilika Lagoon, India. Journal of the Bombay Natural History Society, 101(2), pp.244-251.