Handling practices and post-harvest losses of tuna catches from multi-day boats operating from fish landing site Negombo, Sri Lanka
G J GANEGAMA ARACHCHI, JMPK JAYASINGHE, MJS WIJEYARATNE, W M K PERERA, S JAYASOORIYA, and K HETTIARACHCHI
Tuna is one of the main fish resources from coastal and off-shore areas of Sri Lanka. It has been observed that there is a considerable post-harvest loss in this resource due to poor handling practices. The objective of this study was to study handling practices of tuna catches of multi-day boats (MDBs), infrastructure facilities available and to estimate the post-harvest losses. Tuna fish are mainly caught using gillnets. Nets are soaked for more than 6 hours before hauling. All boats studied were 12±2 m in length and with a single fish hold and a common shutter. The average depth of the fish hold was 2±0 5 m. In a fish hold, there were 5-9 compartments each with 2-4 shelves. Tuna shark and other fish species were stored in the same fish hold. About 4 to 5 lavers of fish were stacked in a shelf with ice. Crushed or flake ice was used in I fish 2 ice ratio. Average temperature of fish in the fish hold was 2 0C, while average storing time of fish in boats was 16±7 days. Total time spent for a fishing trip was 21±9 days. Detergents were used to cleaning in 60% of boats. However the cleaning procedure did not include a sanitizing step. Fish were washed with water near the jetty of fish unloading area. Washing, gutting, selling of fish and dumping of fish wastes were done at a common site. Fish were not iced while displaying on floor for sale. Average temperature of fish in jetty was 17 °C. Based on sensory evaluation, average estimated post-harvest quality loss was 39% while estimated commercial post-harvest loss as 14%.
Prolonged soaking time of gillnets, inadequate icing of fish, higher temperatures in fish holds over-stacking of fish in fish holds, long storing time of fish in boats, use of polluted ice and water and inadequate infrastructure facilities to handle fish at the landing site contributed for the post-harvest quality deterioration and losses of tuna catch in the MDBs in Sri Lanka.