Present Status of Aquatic Resource and Its Catch of Mogra River in Bangladesh

Bangladesh is very rich in aquatic fauna with a biodiversity.The present study,conducted during 2015 to 2019,recorded a total number of 131 species(104 fish,09 prawn,01 snail,04 crabs,and 13 turtles)belonging to 26 families were identified from the Mogra River and its flood plain.About ten types of fishing gears,different crafts,hook and line were found operative in the river.Increasing rates of using current jal(16.0-26.40%)and Kapuri jal(11.0-16.70%)were identified as detrimental gears destroying different species.The fish productivity was decreased dramatically from 170.63±10.81mt to 134.75±8.02 mt with a decreasing percentage of 6.26 to 21.03%within five years.Three important aquatic species turtiles(Cyclem-ys oldhami,Melanocheelys tquuga and Morenia petersi)became rare and 17 commercially important aquatic species were at the edge of extinction(critically endangered,CR).From the study,67 species were recorded in the endangered(EN)category,20 species vulnerable status(VU),11 species lower risk(LR),07 species Least concern(LC)and 04 Data deficient(DF).To save the existing aquatic species in the studied riverine ecosystem and ensure better liveHhood of the fishes,a team of local management committee,similar to the Hilsa fisheries management technology is needed.

Fish diversity reduction and assemblage structure homogenization in lakes:A case study on unselective fishing in China

Unselective fishing involves activities that target the entire assemblage rather than specific fish species,size classes,or trophic levels.This common fishing approach has been in practice for decades in inland waters in China but its implications for biodiversity remain unclear.We addressed this issue by studying fish assemblages in freshwater lakes(five fishing lakes,one reference lake,and a total of 51 sampling sites)between pre-and postfishing time-periods in Eastern China during 2017–2019.The effects of lake,fishing period,and their interactions on fish abundance,biomass,and diversity indices were assessed.Multivariate analysis was conducted to test for differences in fish assemblages among lakes and between fishing periods.After the implementation of fishing activities,significant reductions in fish species richness,abundance,biomass,and all three life-history strategies(opportunistic,equilibrium,and periodic)were observed in fishing lakes,whereas opposite trends were observed in the reference lake.Compositional similarity of fish assemblages among fishing lakes increased over the threeyear monitoring period.Our results suggest that unselective fishing reduces fish diversity and homogenizes fish assemblage structure in lakes.These findings have important implications for protecting both biodiversity and fisheries in inland waters in China and are applicable to other countries or regions that rely on fish as a major food source.