Dampak Penangkapan Ikan terhadap Keseimbangan Trofik Level pada Habitat Lamun di Kepulauan Seribu, Provinsi DKI Jakarta

Abstract

Fishing impacts of small-scale gears operating on seagrass habitat at Seribu Islands, DKI Jakarta Province, was quantified based on a widely accepted ecosystem measure and the ecology structure and the trophic level (TL) indicators. Trophic level of captured fish was evaluated during period October 2011 to April 2012. Fish samples were taken by means of experimental fishing using a set gillnet. In order to evaluate feeding habit a stomach content analysis that consist of quantity, volumetric and frequency of occurrence methods was conducted. The feeding habit data was analyzed by means of Relative Importance and Preponderance Indexes. Trophic level was analyzed base on three cases which found. Result showed that dominant of captured fish came from Holocentridae, that was redcoat (Sargocentron rubrum) and Belonidae that was spottail needlefish (Tylosurus strongylura) with each proportion 26 % of samples. The further dominant of captured fish fish was striped monocle bream (Scolopsis lineata) with proportion 14,5 % of samples. Size of the mean length of dominant captured fish were spottail needlefish (65,9 ± 21,7 cm), striped monocle bream (17,4 ± 1,4 cm) and redcoat (16,5 ± 1,6 cm). Size of the mean weight of dominant captured fish were spottail needlefish (584 ± 245 gr), redcoat (87 ± 30 gr) and striped monocle bream (77 ± 19 gr). Fish in the study area was dominated by herbivorous and demersal feeders. Many fishes that were captured on TL2 had potential to cause unbalanced trophic level in that fishing ground.