Asosiasi Christmas Tree Worm (Spirobranchus) terhadap Ekosistem Karang di Perairan Pesisir Tenggara Pulau Weh Kota Sabang Provinsi Aceh

Abstract

The coral ecosystem in the waters of Weh Island has experienced severe damage due to bleaching, so that the remaining coral colonies in the waters of Southeast Weh Island, namely Beurawang and Jaboi, are massive coral colonies such as Porites. Massive corals can survive the bleaching phenomenon but are vulnerable to the presence of other species such as turf algae and Spirobranchus tube worms (Christmas Tree Worm). The purpose of this study was to analyze; (1) the existence of Spirobranchus species, (2) the density of Spirobranchus during the West and East monsoons, (3) the condition of the coral occupied by the Spirobranchus population, (4) the association of Spirobranchus density with coral conditions, (5) analyzing the physical-chemical factors of the waters that most influence the density of the Spirobranchus population in the waters of Beurawang and Jaboi. and (6) produce a model of the influence of physical-chemical factors of water on the density of Spirobranchus. This research produced; (1) Spirobranchus recommendation as a bioindicator of coral reef health, (2) theory about Spirobranchus density on coral cover, and (3) model of the influence of physical-chemical factors of water on the density of Spirobranchus in Beurawang and Jaboi waters, Weh Island, Aceh Province. The study was conducted in two periods, namely the West Monsoon (May 2022) and the East Monsoon (October 2022) at Beurawang and Jaboi stations. The results showed that the Spirobranchus found included S. corniculatus, S. gaymardi, S. Cruciger, and Spirobranchus sp. The density of Spirobranchus in the East monsoon wind at Beurawang and Jaboi stations was higher (27.61 individuals/ 30 m2), than the West monsoon wind (22.50 individuals/ 30 m2). The condition of the coral occupied by Spirobranchus with a density value of 17.38 individuals/30 m2 (Beurawang) and 7.68 individuals/30 m2 (Jaboi) is in good condition. However, if the individuals are more than 20, the condition of the coral can experience a decline in health due to erosion on the surface and the emergence of depressions in the coral.The association of Spirobranchus with coral conditions during the West and East monsoon winds in Beurawang waters has a 'Strong' relationship (0.771) and 'Very Strong' (0.888), while the association in Jaboi waters has a 'Strong' relationship (0.719 and 0.722), then the physical-chemical factor of the waters that has the most influence on the density of Spirobranchus is Salinity with an R-Square value of 14.4%.