Conditions of Megabenthos on Coral Reef Ecosystem in Seribu Islands National Park, Jakarta, Indonesia

Seribu Islands National Park is located off the north coast of Jakarta and consists of 110 islands. This study aims to determine the distribution and density of megabenthos in coral reef ecosystems in the Seribu Islands National Park. This research was conducted in November 2021 in the Seribu Islands National Park waters. Megabenthos observations were carried out using the Benthos Belt Transect method, a development of the Belt Transect Method for monitoring megabenthos combined with the Reef Check Benthos method. Based on observations in the waters of the Seribu Islands National Park, five types of megabenthos were found, including clams (Tridacna sp.), lola (Trochus sp.), Crown-of-torns starfish (Acanthaster planci), drupella (Drupella sp.), and sea urchins (Diadema sp.). The highest density of megabenthos was found on Kayuangin Genteng Island, with a density of 8,786 ind/ha, while the lowest was on Peteloran Barat Island, with 429 ind/ha. Based on the type of megabenthos at all observation stations, the most abundant megabenthos found was Diadema sp., with a density of 43,397 ind/ha. In comparison, the least was Acanthaster planci of 214 ind/ha. Megabenthos in the Seribu Islands National Park waters are in various conditions.