Effects of abiotic environmental factors on fish yield from traditional stilt fishery in

Stilt fishing is one of the traditional methods practiced in shallow water only in Southern coastal belt of Sri Lanka. Fishing is done with a rod and line while sitting on a cross bar tied to a wooden pole driven into the coral reef. This method of fishing has existed for more than 50 years. The fishing starts when the fish return to the reef during the day time. This study was carried out to investigate the relationships between fish yield of the stilt fishery and the abiotic environmental factors in the fishing area.Study was carried out from November 2007 to June 2008. Three fishing sites were selected at Kubalgama,Talpe and Goviyapana in the Southern coastal belt of Sri Lanka. The selected sites were weekly visited for data collection. The fish catch and effort data were recorded and catch per unit effort (CPUE) was calculated for each sampling site. Daily tidal variation was recorded using a tide pole and the rainfall data was obtained from Meteorological Department. The phases of the moon on the sampling dates were also recorded.Only two species of fish, Blue line herrings (Herklotsichthys quadrimaculatus; Clupeidae) and Big eyed scads (Selar crumenopthalmus; Carangidae) were caught at all the sites. The catch per unit effort among three sites was significantly different (p> 0.05) with a range from 0.44 – 1.26. Fish yield did not relate to the tidal variation in all the sites. Fish catch linearly increased with the lunar phase (r² = 0.81) in the first three quarters. Comparatively low fish catches were recorded during the fourth quarter than the third quarter of the lunar phase. There was a significant (r² = 0.93) positive linear relationship between CPUE with rainfall in stilt fishing. According to the results lunar phase and rainfall may have affected the fish migration towards the reef area as such affecting the yield of H. quadrimaculatusand S. crumenopthalmus in the shallow coastal waters in Southern Sri Lanka