Status of the fishery of flying fish off northwestern coast of Sri Lanka and the effect of lunar pattern on catchability
M.D.S.T. DE CROOS
In Kandakuliya of the Kalpitiya peninsula of Sri Lanka, a seasonal fishery for flying fish exists. The fishing operations are mainly carried out by 37 FRP boats, using gillnets of 3.4 cm and 4.5 cm stretch mesh sizes. In the present study, the fishery was investigated in two consecutive fishing seasons: from October 2002 to April 2003 and from October 2003 to April 2004. Total catch, effort and catch per unit effort (CPUE) showed seasonal variations. During the period of investigation, the highest catch was in November 2002 while the lowest catch was reported in March 2003. Fishing effort was high in November 2002 and remained at a more or less steady level till February 2003. The mean CPUE varied from 102 ± 37.8 to 224 ± 82.7 kg boat-1 day-1. Total production from this fishery during the study period, was calculated as 488.2 and 519.1 tonnes for 2002/2003 and 2003/ 2004 seasons respectively. As the CPUE has not declined during the last decade and as fishing effort has declined, it can be concluded that at present, there is no danger of overexploitation of flying fish stocks off northwestern coasts of Sri Lanka. CPUE values recorded during the full moon periods were found to be significantly lower than those recorded during the new moon period and quarter moon periods (P<0.0001). As such, influence of lunar pattern on the fishery of flying fish should be considered in defining management strategies for the fishery.