The potential of buoyant fish attractor (BFA) substrates in supporting aufwuchs growth as a new food source in euphotic zones of Lake Maninjau

Abstract

Abstract “Buoyant Fish Attractor” (BFA) is an artificial floating substrate placed in the euphotic zone of a lake. This substrate is expected to support the conservation of native fish in a lake. The BFA used in this study was an inverted pyramid which was made of wood or bamboo with a size of about 200 cm in length, 200 cm in width, 80 cm in height and equipped with PVC pipes as a buoy. Three types of a substrate mounted on BFA were wood frames, plastic brushes with 40 cm in length and a diameter of 15 cm, and palm fibers placed in six brick roster. Aufwuch samplings were carried out by four times after a month of BFA installation: in July, August, September, and November 2018. The result showed that on the wood media 37 taxa of benthic microalgae were identified which was consisted of Bacillariophyta 55%, Chlorophyta 18%, Cyanophyta 25 %, Protista 2% and dominated by Synedra ulna. On plastic brush media, 11 taxa of invertebrates were identified: Insecta 72%, Crustacea 18%, Annelida 5%, Bryozoa 5%, Mollusca 0.3% dominated by Chironomus sp. On the palm fiber media, 16 taxa of invertebrates were identified: Crustacea 85%, Insecta 7%, Annelida 6%, and Mollusca 2%, dominated by Chydorus sp. Buoyant Fish Attractor (BFA) has a potential to support the growth of aufwuch as a new food source in the lake’s euphotic zone. The variety of media installed on BFA technology could affect the structure and composition of the aufwuch community.