Fish settlement on reefballs artificial reef and natural coral reef at Buyat Bay and surrounding areas, North Sulawesi, Indonesia

Abstract

Reefballs are internationally patented (1995) and/or copyrighted technologies that allow nearly all natural reef features to be mimicked (Barber, 2000). It is used in over 56 countries for a range of applications including fishing reefs (recreational and commercial), diving reefs, mitigation of dredging and blast fishing, enhancement of coastal develop-ments and multipurpose breakwaters. The rehabilitation of coral reef ecosystem have been broadly acted in Indonesia and even worldwide. Various models and structures of artificial reefs have been made in many countries from different materials. Many of those artificial reefs do not get good attention on their condition after locating them on the sea basin. In 1999, the gold mine operator PT Newmont Minahasa Raya initiated an artificial reef program to provide an incentive to protect local marine resources from bomb fishing, cyaniding and other unsustainable practices. Monitoring program was conducted annually from 2001 to 2009 in 3 locations both in reefball area and adjacent natural reef in 3m and 10m depth at Buyat Bay and surroundings, North Sulawesi, Indonesia. Monitoring was conducted specific for Target and Indicator species with ‘visual census’ method. The survey in 2009 identified 13 families, 29 genera, 81 species and 2,025 individuals inhabiting the reefballs at 3m depth whereas at 10m depth, 14 families, 36 genera, 106 species and 3883 individuals were found. After 9 years monitoring, it was found that one location of Reefball have better fish settlement compared to the adjacent natural reef. One location was in progress to recovery and the location still under the natural reef.