Observations on the prawn fishery of Mangalore coast during 1970-1980

The annual yield of prawns in the Mangalore coast showed considerable fluctuations. The MSY is estimated to be around 1800-1900 t, at an effort level of 28,000 boat-days. The best catch of 3644.6 t and CPUE of 120 kg were obtained during 1973-74. Thereafter, the catch and CPUE declined almost continuously coupled with a reduction in the average size of prawns, even though there was a substantial increase in effort, indicating depletion of the stock. Metapenaeus dobsoni and Parapenaeopsis stylifera contributed to around 85% of the annual avearge catch of prawns. The annual mean length of males and females of M. dobsoni and M. affinis and males of P. stylifera decreased considerably during the present period of observation compared to earlier years. In the case of females P. stylifera, however, the decrease was only marginal