Phosphorus budget in mangrove woods and ecosystems to which are added artificial nutrients and wastewater from shrimp aquaculture ponds

摘要

Mangrove brackish waters are very important for both marine organisms and fishermen, since their primary productivity is very high in order to be supported by abundant nutrients supplies from the land region. Moreover, complex geographical features and the shape of mangrove woods provide marine organisms with excellent shelter for spawning and nursing, thus forming a very biodiverse ecosystem. In developing countries including those in South-East Asia, mangrove forests have been cut down to constructaquaculture ponds, and shrimp aquaculture has developed rapidly and actively to acquire foreign currency. Therefore, mangrove swamps, which act as reservoirs for nutrient load from the land have shrunk, and the self-purification ability of mangrove brackish waters has declined. Worse, wastewater from culture ponds has increased, leading to deterioration of the coastal environment. In addition, the deterioration of water quality, and the sediment produced has deleterious effects on aquaculture itself, resulting in the outbreak of diseases, which in turn leads to the problem of abandoned ponds.