RIASSUNTO
ABSTRACT:
Side-scan sonar observations conducted at Mito artificial habitat site documented the actual positions of both concrete cubic blocks (more than 10,000 units) and scrapped steel boats (43 units) individually. Based on their geographic locations, the concrete cubic artificial reefs could be grouped as 14 reef sets. About 30% of the habitats were deployed out of the acclaimed site area. The actual location of Mito artificial habitat site was centered at 22o46.495''N, 120o9.238''E (WGS84 map datum) with radius of 1,2200 m, which deviates from the acclaimed site center to an extent of about 800 m in distance. For the purpose of artificial habitat site identification and management, a database structure was designed to accommodate positions of habitats, information of reef sets, isobath contours, surficial sediments, and geomorphological characteristics. The linkage of this database structure with geographic information system (GIS) provided a useful and basic tool for modeling and management of artificial habitat ecosystems.
INTRODUCTION
Artificial benthic habitats have long been deployed for promoting the coastal fishery resources. The major functions of artificial benthic habitats include: (i) aggregate organisms to enable more efficient fishing, (ii) increase natural productivity by providing new habitats for encrusting organisms which contribute to food chains, (iii) create habitats for desired target species, and (iv) protect small/juvenile organisms and nursery areas from destructive fishing gears (Chou, 1997). There are literally hundreds of artificial habitat designs around the world, although the materials used are fairly limited in number. Aside from monitoring the fish-attraction effectiveness of a particular habitat, it is necessary to conduct follow-up investigations thereby determining whether or not (i) the habitat is and remains within the officially acclaimed area after installation and (ii) the structure of the habitat is still intact after the passage of a certain period of time.