ENVIRONMENTAL IMPACT OF OYSTER LONGLINE CULTURE

Intensive oyster longline culture in small bays off the southern coast often resulted in anoxia on the sea bed due to the accumulation of pseudofaeces from the suspended oysters. These anoxic problems were more prominent in bays where the seawater circulation was poor.

Furthermore, the high density of oysters on the longlines also results in poor growth and, subsequently, poor profits. To overcome these problems, the distance between oyster farms, the distance between longlines and the number of suspended oyster strings on an individual longline has been regulated as shown in Figures 16 and 17. The regional office of marine extension and the oyster longline culture cooperatives provide information on the proper management of oyster farms, such as a standard model of longline culture system, through a newsletter and on the website. For example, the original styrofoam floats used in the longline culture which could not be disposed off have been replaced by the more durable and environmental friendly plastic floats.