PRESENT STATUS OF THE SHRIMP TRAWL FISHERY IN THE ...

24 P. A. A. T. Jayawardane et al.
Figure 1. Map of the study area
June-July to October-November of both years. The
non-mechanised trawls have shown little variation
in terms of the fishing effort throughout the study.
Catch rates
The CPUE of different components of the
non-mechanised trawls (shrimp, fish and total)
show considerable variations and the total catch rate
is influenced by the catch rate of shrimps to a great
extent. The peak total and shrimp catches were
recorded in January 1998 while the fish peak
catches in January 1999 (Fig. 3). The mean total,
shrimp and fish catch rates for the years 1998 and
1999 were estimated at 19.91, 12.49 and 7.42
kg/craft-day and 19.91, 11.33 and 8.57 kg/craft-day
respectively (Table 1). The catch rates of shrimps
increased from around May-June until August-
September and declined again. In addition high
CPUEs were also observed in November of both
years. It was noted that the period of high CPUEs of
shrimps apparently coincided with the south west
and the onset of north east monsoon of the island
resulting high winds in the west coast (Fig. 3). On
the other hand the period of low catch rates in terms
of shrimps coincided with the north east and the