STRUCTURE OF FISH COMMUNITIES IN AREA OF BUOYANT FISH ATTRACTOR IN LAKE MANINJAUSyahroma Husni Nasution, Octavianto Samir, Rahmi Dina, Gadis Sri Haryani and Nofdianto
Lake Maninjau is one of the natural lakes located in Sumatra, Indonesia. One of the native fish of economic value as a consumption fish on Lake Maninjau is Rasbora spp. The current condition of bada fish fisheries tends to decline. This condition is estimated due to quite intensive fishing and a decrease in the lakeâs environmental conditions. Therefore, it is necessary to carry out an effort to conserve bada fish by using Bouyant Fish Attractor (BFA) to increase the bada fish population in Lake Maninjau so that it can be sustainable and utilized by the community. The study was conducted from April to October 2018. Data collection is carried out inside the BFA and outside the BFA. BFA was installed as many as three in the litoral zone of the lake with a depth of about 1 meter and about 15 meters from the shoreline of the lake. Fish are caught using gill nets with seven mesh sizes, surface trap and bottom trap. In this observation the data included the number and composition, catch trends, to find out the length weight relationship and the condition factor, the dominant native fish species is Rasbora spp. the results of the observation found 12 species of fish consist of five native fish species and seven species of fish introduced. Dominant native fish is Rasbora spp. and dominant introduction fish is Oreochromis niloticus. The dominant native fish catch trend is Rasbora spp. and the highest is found in July both inside the BFA and outside the BFA were 135 and 98 fish, respectively. The dominant introduction fish catch trend is O. niloticus which is highest in July both inside the BFA and outside the BFA were 19 and 58 fish, respectively. Based on the length-weight relationship, the growth of Rasbora spp. is allometric negative. The condition factor value of Rasbora spp. for male and female range between 0.68-0.71. From these results it can be concluded that BFA technology has succeeded in attracting fish populations, especially native fish species, because the availability of new food nets as a food source, shelter from predators.