保護區於1月29日正式成立，旨在保護亞洲僅存的兩種淡水豚：恆河豚（Ganges River dolphin，Platanista gangetica gangetica）與伊河豚（Irrawaddy dolphin，Orcaella brevirostris）。這兩種淡水豚都沒有全球族群量評估的資料，在過去分佈範圍中的許多地區，也已經失去蹤跡，但仍有225隻的恆河豚和450隻的伊河豚存活在桑達本地區。
位在桑達本紅樹林東部的Dhangmari、Chandpai及Dudhmukhi地區的三個保護區，包含了31.4公里的水道，共10.7平方公里的面積。這些新保護區的設立，是由設立在美國布朗克斯動物園的「國際野生物保育協會」（Wildlife Conservation Society，WCS），經執行孟加拉鯨豚多樣性計畫（Bangladesh Cetacean Diversity Project）後所選定的。
自1990年早期即在孟加拉進行鯨豚研究、現任WCS亞洲淡水與海岸鯨豚保護計畫主持人的Brian D. Smith表示，設立保護區是保育恆河豚與伊河海豚的第一步。
孟加拉林業局的林業與野生動物專家Tapan Kumar Dey博士表示，關鍵在於當地人的參與。
為了達成這個目標，孟加拉鯨豚多樣性計畫團隊從18日開始，在桑達本紅樹林週邊的社區舉辦名為「Shushuk Mela」的搭船賞豚活動。而Shushuk 即是當地語言對恆河豚的稱呼。
桑達本的新保護區亦將為其他生存受威脅的水生生物提供保護，如河龜（river terrapin）、日鷉（masked finfoot）與小爪水獺（small-clawed otter）。
Bangladesh has established three new wildlife sanctuaries for endangered freshwater dolphins in the world's largest mangrove ecosystem, the Sundarbans.
Officially declared on January 29, the sanctuaries are intended to protect the last two remaining species of freshwater dolphins in Asia - the Ganges River dolphin, Platanista gangetica gangetica, and the Irrawaddy dolphin, Orcaella brevirostris.
While there is no global population estimate for either species, both have disappeared from major portions of their range but still survive in the Sundarbans. Rough estimates indicate populations of about 225 Ganges River dolphins and 450 Irrawaddy dolphins there.
The IUCN Red List of Threatened Species lists the Ganges River dolphin as Endangered and the Irrawaddy dolphin as Vulnerable to extinction.
Freshwater dolphins are among the most threatened animals on Earth because human activities, such as dam construction, toxic contamination and unsustainable fisheries, disturb their habitat. Population surveys find Ganges River and Irrawaddy dolphins living in the very waterways where human activities are most intense.
The three sanctuaries - in the Dhangmari, Chandpai and Dudhmukhi areas of the Eastern Sundarbans mangrove forest - safeguard 19.4 miles (31.4 km) of watery channels with a total area of 4.1 square miles (10.7 sq km).
The newly-protected areas were identified as dolphin hotspots by the Bangladesh Cetacean Diversity Project, a project of the Bronx Zoo-based Wildlife Conservation Society.
These small areas could be the safety net that prevents extinction for these species, says the WCS, in view of the recent extinction of another freshwater dolphin - China's Yangtze River dolphin whose last confirmed sighting was in 2002. Fatal entanglement in nets and habitat degradation killed off this species after it had survived in the Yangtze River for more than 10 million years.
"Declaration of these Wildlife Sanctuaries is an essential first step in protecting Ganges River and Irrawaddy dolphins in Bangladesh," said Brian D. Smith, director of the WCS's Asian Freshwater and Coastal Cetacean Program, a scientist who has been studying cetaceans in Bangladesh since the early 1990s.
The Bangladesh dolphins are threatened by fatal entanglements in fishing gear and depletion of their prey from the by-catch of fish and crustaceans in fine-mesh "mosquito" nets used to catch fry for shrimp farming.
The surviving dolphins are at risk from increasing salinity and sedimentation of the rivers caused by sea-level rise and changes in the availability of upstream freshwater flow.
"As biological indicators of ecosystem-level impacts, freshwater dolphins can inform adaptive human-wildlife management to cope with climate change, suggesting a broader potential for conservation and sustainable development," said Smith.
Now that the three sanctuaries have been officially declared, Bangladesh officials will post signs so that local fishermen do not enter the protected areas.
Dr. Tapan Kumar Dey, conservator of forests and wildlife with the Bangladesh Forest Department, said, "A critical component will be to engage local human communities."
To achieve that goal, starting on Saturday, the Bangladesh Cetacean Diversity Project will bring a boat-based dolphin exhibition called the "Shushuk Mela" to local communities bordering the Sundarbans mangrove forest. Shushuk is the local word for the Ganges River dolphin.
This month-long traveling exhibition is intended to raise awareness about the new wildlife sanctuaries and engage local fishermen and other community members in discussions on adaptive management practices needed to ensure human-dolphin coexistence.
The new wildlife sanctuaries in the Sundarbans will provide protection for other threatened aquatic wildlife, including the river terrapin, masked finfoot, and small-clawed otter.
Bangladesh has been recognized as a critical place for freshwater dolphin survival. In April 2009, based on research by Smith and others, the Wildlife Conservation Society announced the discovery of the world's largest population of nearly 6,000 Irrawaddy dolphins in the country. A portion of this population shares habitat with the endangered Ganges River dolphin, whose range extends all the way upstream to the shadow of the Himalayas in Nepal.