One particular area in the Bay of Bengal (under Bangladesh) is shrouded in mystery. It is called the Swatch of No Ground. Some say there are sunken treasure ships here, but we’ll get to that when somebody finds it!
As of now, the area in its entirety remains unexplored. However, a small part of it is Bangladesh’s first Marine Protected Area, as declared by the Ministry of Environment and Forest.
Swatch of No Ground is a trough-shaped marine canyon that is on the Ganges-Brahmaputra delta. Also known as the Ganga Trough, it is one of the largest sediment fans in the world. Sediment fan, what is that? A sediment fan forms when sediments from surrounding areas accumulate in an area by means of rivers and its tributaries and distributaries. This one’s such submarine sediment fan, forming a canyon in the Bay of Bengal, and it is a part of the Bengal Fan, world’s largest underwater ravine.
The 163,600 ha Swatch of No Ground Marine Protected Area was declared a protected area on 26 October 2014. It is an approximately 14 km deep underwater trench, home to a number of globally threatened species of marine animals. There are endangered dolphins and eight species of whales including the fin whale, hunchback whale, common sperm whale, killer whale and Bryde’s whale.
The Swatch of No Ground is located very close to the Sundarban area, just about 30 km from the Dublar Char Islands. Studies have shown that apart from the recorded marine species, there are still many undocumented species that are endemic to this region.
There is some controversy regarding the origin of Swatch of no Ground. However, it is generally believed that during the Pleistocene (2-0.1million years ago) lower sea level, Ganga-Brahmaputra River was discharging its sediment load directly on the shelf edge.
Combination effect of river flow and turbidity currents generated at the shelf break and upper slope was responsible for the formation of the Swatch of no Ground. Evidence from the Bengal Deep-Sea Fan also tends to support this view. It has been observed that turbidity currents during the Pleistocene lower sea level dominated sedimentation on the Bengal Deep-Sea Fan.