The densely populated country of Bangladesh is a land crisscrossed by an intricate system of hundreds of rivers, including the mighty Ganges-Brahmaputra-Meghna river system. These enormous freshwater inputs, combined with the bio-productivity from the world’s largest mangrove forest, feed into the Bay of Bengal – of which 166,000 square kilometers belong to Bangladesh.
Extraordinary oceanographic conditions in these waters, including a part of the submarine canyon known as Swatch-of-No-Ground, support hugely diverse and relatively large populations of sharks, dolphins, whales as well as fisheries vital for the country’s food security and economy. To better understand and safeguard this marine diversity, WCS and local partners are currently conducting the Bangladesh Marine Megafauna Survey 2017/2018, a unique and truly exciting undertaking. The survey retraces the original transect lines drawn along the entire coast of Bangladesh for a previous survey carried out by WCS back in 2004.
That original effort discovered the world’s largest population of Irrawaddy dolphins, small beakless marine mammals that frequent the country’s coastal waters. Other discoveries included some of the largest documented populations of Indo-Pacific bottlenose and humpback dolphins and finless porpoise. Marine mammals such as spinner and spotted dolphins and the Brydes whale were found to be common farther offshore. This year’s survey will include not only marine mammals, but other iconic species such as sharks, rays, and marine turtles. Started in late December, the survey is being carried out across a distance of more than 1,500 kilometers over a period of 40 days – with two vessels, 20 team members, and 11 crew. Two traditional local fishing boats were modified to accommodate the survey team. Observers will search for marine mammals from an extended top deck and sleep onboard in a custom built cabin constructed from bamboo. The vessel is equipped with basic navigation and communication equipment, as well as an onboard kitchen. Whatever these basic boats lack in comfort, the team makes up for with enthusiasm for the expedition. The goal of this survey is to provide the scientific basis for new Marine Protected Areas (MPAs) in Bangladesh. This is not the first time that WCS has provided scientific expertise for an MPA declaration. In 2014 the Government of Bangladesh followed WCS’s recommendations for declaring the country’s first MPA, covering waters from the head of the Swatch-of-No-Ground to the Sundarbans mangrove forest. In combination with previous research results and information from citizen science networks that WCS operates among fishers and landing site data collectors, WCS aims to identify key areas that support significant numbers of marine megafauna and vital fisheries. We will then assist the Government of Bangladesh in achieving its national commitment to protect 10 percent of its marine waters.
After extensive preparations and a two day intensive training program covering species identification, survey and fish catch sampling theory, equipment handling as well as a safety briefing at the WCS office in Khulna, the survey team finally set sail on December 22nd for the Bay of Bengal. Our findings will undoubtedly produce a valuable new body of information on Bangladesh’s marine wildlife and help protect the country’s natural heritage.
We look forward over the coming weeks to share our adventures and discoveries in the amazing waters of the Bay of Bengal.
Elisabeth Fahrni Mansur is Director of Education and Livelihoods for the Bangladesh Program at WCS (Wildlife Conservation Society).