Environmental characteristics and development prospective of sea cage aquaculture in Morotai Island Regency

Abstract

Sea cage aquaculture, if well managed, is one of the most successful and profitable marine aquaculture systems and has demonstrated substantial economic benefits. A relatively suitable sea or coastal water quality, as well as availability waters areas, are the major supporting factors that enable successful sea cage culture. This study explores the environmental characteristics and the potential development of sea cage culture in Morotai Island Regency, North Maluku Province. This study employed a survey method by which environmental data were collected following a random stratified technique in geographical information systems (GIS). The results of water quality analysis generally indicated that the study areas are highly suitable for sea cage culture. The suitability of engineering design based on water depth and safety issues relating to extreme weather and highly exposed coastal areas was the only significant factor that directly limits the suitable areas. After the integration of water depth and safety factors variable into the final spatial analysis, only 398 ha of waters were found suitable for sea cage culture. However, previous studies have suggested that for the sake of sustainability, only a maximum 10% of suitable waters can be used for the sea cage culture. Therefore, this study has recommended no more than 15 units of cages per hectare with a dimension of 8 x 8 m2 per cage or only the 597 units to be allocated for the whole identified suitable areas. A lack of marine aquaculture infrastructure and an inadequate as well unreliable supply of quality fish seed (fry) have been the major constraints for the sustainable production and operation of sea cage aquaculture in the study areas. With a better understanding of the existing suitable areas and its maximum production carrying capacity, aquaculture decision-makers can develop effective and efficient strategies to help improve the product for the sustainability sea cage culture activities in this region.