Abstract:
Koggala lagoon is located in Galle district with a significant contribution to the fishery
sector of Sri Lanka. The inevitability of illegal fishing practices causing a threat to the
commercially important fish populations due to strengthened demand, higher prices, and
emerging competition in the market, had also been a serious issue in the fishery of
Koggala lagoon. The objectives of the present study were to, identify the illegal fishing
methods practiced in the lagoon and quantify the approximate illegal production. A selfadministrated questionnaire survey was designed and pre-tested to collect sociodemographic details of the sixty fishermen and also average production data using illegal
fishing gears over three months from October to December 2019. Catch data were
collected to calculate the Catch per Unit Effort (CPUE) in common fishing gears. The
Garret ranking technique was applied to assess the degree of severity of the fishing gears
according to the lagoon fishermen’s perception. Results of the questionnaire survey
indicated that gillnets (97%) with less than 3 ½” mesh size and monofilament nets (48%)
were the most common illegal fishing gears used among the lagoon fishermen. Among
the wide range of mesh sizes of the gillnets, 57.15 mm (2 ¼”) size was frequently
(23.3%) used for fishing in the lagoon. According to the fishermen’s perception on the
weight of the harvest and the size of the juveniles, the fixed purse net was found to be the
most detrimental gear used in the lagoon (1.79 kg hour-1
). However, considering the
average catch data, the fixed purse net (7.64 kg) was also the most efficient gear used in
the Koggala lagoon. The current study revealed that illegal fishing is very common in the
lagoon violating government rules and regulations. Therefore, active legal enforcements
and monitoring on illegal fishing practices such as usage of over-small mesh nets and
monofilament nets are extremely important in preventing overexploitation of fish
populations.
Keywords: Koggala lagoon, Illegal fishing, Sustainable utilization, Garret’s ranking
technique, Socio-demography
