MUHAMMAD SHALAH UDDIN KABIR
Department of Fisheries Biology and Genetics, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
MD. RAFIQUL ISLAM SARDER
Department of Fisheries, Bangladesh
MOHAMMAD MATIUR RAHMAN
Department of Fisheries, Bangladesh
MD. FAZLUL AWAL MOLLAH
Department of Fisheries, Bangladesh
MOHAMMAD ABU TAHER
Department of Fisheries, Bangladesh
Mohashol, Tor tor, Endangered, Conservation, Someshwari
Conservation and Biodiversity
Someswari river, the habitat of mohashol, is one of the rivers which lost her golden past in respect of water flow, fish species diversity as well as aquatic biodiversity in recent years. In India this river is also known as Simsang river which is the longest river and cultural icon of Garo Hills of Meghalaya, one of the important hill states of North-East India. Someswari river originates in the Nokrek Peak (now declared as Nokrek Biosphere Reserve) and is located about 1412 meters above from the mean sea level (MSL). It lies 13 km Southeast of two faults and along with the Northern faults, the river flows towards the East for about 45 km. It drains the hills between Tura and Arbela ranges and the valley of Rongdi. The river has a winding course. At first it flows in an East wide direction for about 75 km and then takes a turn towards the South and flows in a Southerly direction until it leaves the hills and enters the plains of Bangladesh (Sarma et al. 2009). In Bangladesh it flows through the Susang-Durgapur and other areas of Netrakona till it flows into the Kangsha river in Netrakona district (Fig.1). A branch of the river flows towards Kalmakanda and meets the Balia. Another branch of the river flows into the haor areas of Sunamganj district and flows into the Surma river. Before joining Kangsha river, it flows across the Bijoypur and Ranokhong from northern to southern Jaria-Jhanjyle through the Sibganj bazaar (West bank) and Durgapur Sadar (East bank). In November 1991, a small abandoned channel north of Durgapur with a flow direction towards the east was rejuvenated after 1990 (Alam 2004). This small meandering channel was locally named Atrakhali channel. However, except in rainy season there is no evidence of water flow in the main river and Atrakhali channel. During rainy season, fishers used to collect the mohashol from Someshwari river and its adjacent floodplain by operating various fishing gears locally called khorajal, dharma jal, jhakijal, the lajal and rear them in ponds with other carp species. A major portion of captured mohashol attains 100-250 g, though fish weighing of 3.0-4.0 kg are also trapped very rarely by fishers. After two to three years of rearing, fishers sell the fish at high price to affluent customers. But due to climate change and many other factors, the availability of mohashol is decreasing day by day in Bangladesh. According to the fishers on the bank of the Someshwari river, 6-7 mohashol species are available, but in Bangladesh two species i.e., T. tor and T. putitora are found. The rural people of Durgapur called the mohashol as mashol and believe that it can make any impossible to possible. Moreover, it has tremendous demand as gift. The data on the availability of mohashol and its habitat i.e. the river Someshwari is limited. Monitoring population performance of mohashol in River Someshwari is problematic due to the logistical difficulties as well as to reach to the breeding and nursery grounds of the fish towards upstream due to border crossing restriction imposed from both Bangladesh and Indian Governments. Thus, there is a paucity of available data to access the current status and vulnerability of stocks in this river. Chakraborty and Mirza (2010) studied the aquatic resources of Someshwari river and gave a scenario of the stocks of fish by obtaining data through market survey and interaction with local fishers. This study along with personal interview and Focus Group Discussion (FGD) with local fisher folk at Shibganj bazaar, Atrakhali, Kumargata, Mou, Teribazaar, and Ranikhong point of the Someshwari river and with the Upazila Fisheries Officer, Durgapur, Netrakona (personal communication) provided information about the availability of Tor tor and Tor putitora. In the globe one third of the freshwater fishes are becoming threatened and some of the mare in the verge of extinction (Dudgeon, 2012). Freshwater fishes are increasingly threatened by a range of factors, including habitat loss, over-exploitation and biological invasions (Dudgeon 2012, Gozlan et al. 2005). Over-exploitation, water pollution, flow modification, destruction or degradation of habitat, and invasion by exotic species can be grouped under five interacting categories as major threats to freshwater biodiversity, with global-scale environmental changes superimposed upon them all (Dudgeon et al. 2006). These globally escalating threats have led to freshwater biodiversity falling into a state of crisis (Vorosmarty et al. 2010) and becoming more imperiled than its marine or terrestrial counterparts (Strayer and Dudgeon 2010). In South Asia, population growth and its related development has led to heavily degraded water quality with threats such as deforestation leading to sedimentation, poor wastewater treatment, agricultural and industrial expansion and pollution, huge levels of water abstraction, and construction of dams leading to altered flow regimes and saltwater intrusion (Babel and Wahid 2008).
Bangladesh J. Fish. (2021) 33(1) : 157-166
Journal