GOLT as a clarification to Fishers’ perceptions over recent trends in the pelagic fish catches in the Indian Ocean by Sri Lanka: a preliminary analysis

In Sri Lanka, multi-day fishing operations are carried out by inboard multiday boats (IMUL). These boats usually target pelagic tuna and tuna-like species using drift gillnets, longlines and a small-scale surrounding net called ring nets. that although there was an increase in pelagic fish catches until around 2010, particularly yellowfin and skipjack tuna, catches of almost all pelagic fish species had a spectacular decrease over the years according to the IOTC data. . Fishermen also complaining on the same aspect claiming that there have been declining trends in the catch composition of target pelagic species. Results of a questionnaire survey indicated 64.7% of the skippers were of the view that the shifting of productive fishing locations of pelagic species was possibly due to changes in oceanic characteristics.  An attempt was made to explain the trends of and fishers’ attitudes about changes in pelagic catches in the Indian Ocean via GOLT theory. Results of GOLT analysis indicated that, pelagic fish species in the Indian Ocean off Sri Lanka can be considered to be susceptible to deoxygenation due to elevated sea temperature. It is therefore imperative that the regional fisheries management organizations such as IOTC consider, when defining data collection and analysis process and regional fisheries management plans, the possible shifting of pelagic fish stocks due to deoxygenation associated with increased sea surface and sub-surface temperature as an area of concern in addition to control of the amount of fishing