Species composition and abundance of small fishes in seagrass beds of the Karang Congkak Island, Kepulauan Seribu National Park, Indonesia

Abstract

It is extensively recognized that seagrass meadows have been defined as nursery ground for fish. In this study, we investigated species composition and abundance of small fishes in seagrass beds of Karang Congkak Island, Kepulauan Seribu National Park from November 2018 to March 2019. In total, about 10,000 individuals of 46 fish species belonging to 26 families were captured using a seine net at four fix stations. The major families graded by species number were Labridae, Apogonidae, Gobiidae, Siganidae, and Atherinidae. More than 90% of fish was juvenile and mostly economically important species and reef-associated fish. Majority of fish juveniles inhabit seagrass beds were categorized as temporary resident and regular visitors. It was observed that the top five ranked fish species in abundance were Spratelloides gracilis (33.4%), Stenatherina panatela (19.5%), Siganus canaliculatus (13.2%), Gerres oyena (11.8%) and Siganus spinus (5.9%). There was a propensity that species richness and diversity were higher in areas with higher seagrass coverage. However, two-way ANOSIM revealed fish abundance was not significantly different spatially and temporally (p>0.05). Predominant trophic function of fish were zooplanktivores and crustacivores. The present study, therefore, identified seagrass beds of Karang Congkak Island as feeding habitats and shelter for fish juveniles.