COLOSSAL LOSS OF FISH BIODIVERSITY DURING FRY COLLECTION IN THE RUPSHA RIVER

Abstract

A key challenge for sustainable fish production is the loss of fish biodiversity caused by the indiscriminate capture of non-target creatures, particularly in Bangladesh's inland and coastal regions. In addition to serving as a crucial navigational channel in Bangladesh's coastal regions, the Rupsha River in Khulna City is also home to over 15000 fishermen who harvest fish and shrimp fry. Therefore, a study was carried out to assess the existing fry collection scenarios, fish bycatch and its impact on the biodiversity to enhance the production and biodiversity of the Rupsha River. Between May 2022 and July 2023, information was gathered from stakeholders through a combination of personal observation, focus groups, and cross-check interviews. In this study, Macrobrachium rosenbergii and Penaeus monodon fry were collected from wild sources by fixed blue net (FBN) and drag net (DN) as target species. For FBN compared to DN, efficiency and survival rate were both higher. FBN and DN caught 20 different bycatch species, including one highly endangered (Channa striata), four vulnerable species, and four commercial species. During the study period, the mortality rates of bycatch was 50%. The assessed value of the commercial adult species lost during fry collection stands at 1,245 BDT (Bangladesh Taka) per person per day, whereas the earnings of the fry collectors’ amount to 80 BDT per day. Hence, it is imperative to rigorously enforce a ban on larvae fishing through community participation and integrated coastal zone management to preserve aquatic biodiversity and protect the livelihoods of the coastal population.