Fish colonization of the artificial reef at Gusung Batu Lampe Muara Badak, Kutai Kartanegara, East Kalimantan, Indonesia: a preliminary study

Abstract

Background: Artificial reefs can be utilized as new habitats to restore fish populations in degraded coral reef environments. This study evaluated the restoring ability of the artificial reef set at Gusung Batu Lampe should be investigated by observing the fish population colonizing the reef. Methods: A fish visual census was applied to identify the species and count their numbers at the site. Underwaterline transect was used to limit the observation area to 200 m2 measured with 50m roll meter. The reef structure comprised 34 tetrahedral concrete blocks arranged in a row, which was 60 cm x 60 cm at the base, 35 cm x 35 cm on top and 60 cm high, and has four holes. Two scuba divers descended, one to ensure the safety of the divers and the other to observe the fish. Each dive took place over 30–45 minutes, and was conducted at 09:00, 13:00 and 17:00. Surveys were performed four times: in November and December 2016, and in January and July 2017. Results: Results showed that fish colonization composed of 180 to 283 individual number with taxa between 13 and 25 species. Number of fish in colonization was found significant difference among observation times, and fish species from the family Chaetodontidae were observed in every survey. Conclusions: A total of 38 fish species from 16 families were identified colonizing the reef during surveys, and in four month observation the fish colonization size increased from the fish density of 1/4.444 m2 to 1/1.481 m2, confirming the ability of the reef to restore fish population.