LOSS OF AQUATIC FAUNA DURING COLLECTION OF Penaeus monodon POST LARVAE IN COX'S BAZAR COASTS, BANGLADESH

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. To analyze the quantity of black tiger shrimp’s (Penaeus monodon) post larvae (PL) and estimate the harm to various aquatic species during shrimp PL collection, samples were collected monthly (January to December 2021) from four different selected spots (Sonarpara, Rezukhal, Rajarchora, and Marishbuniya) on the Cox's Bazar coasts by using a small-sized marine set bag net (MSBN). The investigation revealed that at the time of collection of every 100 PL of P. monodon approximately 2,641 PL of crustacean, 186 fin fish larvae, 807 PL of crustacean, 145 fin fish larvae, 689 PL of crustacean, 84 fin fish larvae, and 614 PL of crustacean, 237 fin fish larvae were cruelly destroyed from Sonapara, Rezukhal, Rajarchora, Marishbuniya stations repectively. P. monodon larvae were found to occupy a small portion of the total annual catch composition, such as 3.42%, 9.50%, 11.45%, and 10.51% in Sonarpara, Rezukhal, Rajarchora, and Marishbuniya, respectively. The highest rate of P. monodon capture (10.44 %) was recorded at Rajarchora station, while the lowest rate was recorded at Sonarpara station (3.21%). Although P. monodon PL is available throughout the year, its density was high in Razarchora station. A higher number of P. monodon PL was found in the months of October and March in all stations. Data revealed that in the rainy season (July, August, September and October), larvae of P. monodon were found to be higher compared with the other seasons in all stations. Whereas, the abundance of P. monodon reduced during the winter season (November, December, January and February). The findings show that the current seed harvesting approaches are severely harming other valuable aquatic fauna, which will ultimately put negative impact on the faunal diversity, natural productivity and self- recruitment pattern of mother stock.