Engineering and deployment of artificial reefs for a community-based fishery resource management project at Mararison Island, Antique, Philippines

Abstract

This paper describes the self-initative of the island's inhabitants in the fabrication and deployment of concrete artificial reefs (ARs) using indigenouse materials as well as appropriate technology at Mararison Island, Antique, Philippines. Deployment of ARs is one of the developmental components of SEAFDEC/AQD assisted community-based fishery resource managment project. To determine transport and deployment problems, two prototype prefabricated modules, building blocks and pipe culverts, were deployed in May 1994. The building blocks module consisted of 10 150x200x2000 mm concrete culvert units arranged in pyramidal configuration of 5,4,3,2, and 1 layers.

AR modules designed to provide more surface area and crevices were fabricate in segments at a maximum of 1.47 KN/unit to ease transport and deployment.After attaining its concrete strength, the units were manually hauled from fabrication site to a bamboo raft and towed by a motorized bance to the deployment site. The raft have a rectangular opening at the middle where the units were manually lowered, one at a time, useing rope and pully. Local community divers using surface-supplied are compressors assemled the modules in block and in pyramidal configuration. A relatively flat boottom, 18 m water deep, and the presence of exploited coral reefs in the area were among the factors considered in setting up the ARs.