Influence of cage culture on wave attenuation at the front mangroves

Abstract

Mangroves are trees and shrubs that grow in saline coastal habitats in the tropics and subtropics, mainly between latitudes 25 ° N and 25 ° S. The saline conditions tolerated by various species range from brackish water, through pure seawater (30 to 40 ppt), to water of over twice the salinity of ocean seawater, where the salt has become concentrated by evaporation. Mangrove also help to protect coastlines against erosive wave action and strong coastal winds, retain concentrate and recycle nutrients and remove toxicants, provide resources for coastal communities, and important breeding ground for many fishes, crabs, prawns and other marine animals, essential for sustaining a viable fishing industry. Cage culture is one of the shore morphology that available at mangroves. Cage culture is an aquaculture production system where fish are held in floating net pens. Cages are widely used in commercial aquaculture overseas and individual cage units come in all shapes and sizes and can be tailored to suit individual farmer's needs. The study to know their influence to the wave that goes to the mangrove is important in order to identify the factors that threaten this habitat. From the result, cage culture is not reduce the wave that passed through it but increase the wave height and wave energy and affected the mangrove behind them. It is because the floating cage is giving a reflectant and makes the wave bigger and stronger. Cage culture make a new wave when they are going upward and downward when wave passed through them and make the passed wave higher in height and energy. More study and research are needed in order to solve this problem. Cage culture is giving much benefit in economy sector but in the same time the precious habitat is in danger.