LOSS OF AQUATIC FAUNA DURING COLLECTION OF Penaeus monodon POST LARVAE IN KUMIRA, COASTAL REGION OF CHATTOGRAM

Abstract

In Bangladesh, due to a lack of hatchery-produced post-larvae compared to demand, shrimp farming is dependent on wild post larvae (PL). The activity of indiscriminate wild PL fishing has a notorious impact on biodiversity in coastal ecosystems due to significant amounts of by- catch. Samples were collected from three different selected stations using push and pull net in Kumira, Chattogram from January to December 2021 to analyze the quantity of black tiger shrimp (Penaeus monodon) post larvae (PL) and estimate the harm to various aquatic species during shrimp PL collection. The investigation revealed that approximately 261 crustacean, 53 fin fish and 297 unidentified larvae in station-1, 222 of crustacean, 47 fin fish and 231 unidentified larvae in station-2, 196 of crustacean, 52 fin fish and 224 unidentified larvae in station-3 were cruelly damaged at the time of collection for every 100 PL of P. monodon. P. monodon larvae were found to occupy a small portion of the total annual catch composition, such as 14%, 17% and 18% at station-1, 2 and 3, respectively. Higher number of P. monodon PL was found in August in all three sites. Finfish larvae were more abundant in rainy season (July to October) than other time of the year. P. monodon PL was also found to be higher in rainy season compared with the other groups. Whereas, their abundance reduced during winter season when PL of Macrobrachium lamerrei was in peak position. The statistical analysis revealed that, there was no significant difference (P > 0.05) among mean catch composition from different sampling stations. Also, the mean number didn’t significantly differ with the change of different season. But the monthly mean catch composition of three sampling stations showed significant variation (P < 0.05). The findings show that the current seed harvesting approach severely harms other valuable aquatic fauna, which has an impact on the faunal diversity, natural productivity and self- recruitment pattern of mother stock.