Ranau Lake, the second biggest lake in Sumatra Indonesia, is inhabited by various freshwater fishes. The local people depend largely on fish resources for their life and use gillnet fishing gear for their fishing activity. The current... more
Ranau Lake, the second biggest lake in Sumatra Indonesia, is inhabited by various freshwater fishes. The local people depend largely on fish resources for their life and use gillnet fishing gear for their fishing activity. The current research focused on selectivity and effectiveness of different gillnet mesh sizes as a tool to fisheries plan management in the lake. Research was carried out in twelve times of direct observation on fishing activity within two days per month from March to October 2013 and February to May 2014. The gillnets used for experimental fishing were constructed with seven different of mesh sizes such as: 3.5, 3.0, 2.5, 2.0, 1.75, 1.5, 1.25 inch. Total catch from each piece of gillnet, was recorded from five to ten selected fishers. Fish samples were collected for species identification and for length and weight measurement. Fish identification was done by comparing the morphometry and merystic characters of the sample to reference books. Results show that different gillnet mesh sizes succeeded to catch about 17 species of fish. As selective fishing gears, gillnet seems to be size selective rather than species selective. Gillnet mesh sizes are correlated negatively with the number of fish catch. The smaller mesh size succeeded to catch relatively high amount of fish, but the gear tends to be not selective. For sustainable fish utilization, it suggests that larger gillnet mesh sizes (> 2.0 inch) were encouraged to be used by the fishermen.
