Maximum sustainable yield estimate for Brown shrimp, Metapenaeus monoceros (Fabricius 1798) in marine waters of Bangladesh using trawl catch log

Abstract

Brown shrimp, Metapenaeus monoceros is a major contributor of shrimp trawling in Bangladesh marine waters. This is a key fisheries item owing of its fast growth and short life span. Though, stock assessment is need to be conducted annually, the present study is the maiden effort on the assessment of the stock of M. monoceros in marine waters of Bangladesh. Catch per unit effort (CPUE), the most common pieces of information was taken from trawl catch log between 1986 and 2017 for assessing the status of brown shrimp stock using Schaefer biomass model through MS-Excel and CMSY/BSM interfaces. The standing stock and fishing mortality were assessed to be around 5960 t and 43 %, respectively. The calculated reference points of maximum sustainable yield (MSY) with 95 % confidence interval are optimum biomass B_MSY 5060 t (4190-6110 t) and optimum fishing mortality F_MSY = 61 % (51-63 %). The average annual catch of last two decades was 2793 t, below assessed MSY of 3090 t (2920-3260 t). The stock is probably going to be of satisfactory size with sustainable exploitation close to MSY. Thus, management would be well advised not let to increase catches but to maintain them at the current level.