Mariculture's Two Side Effects on Environment and Their Utilization in Practice
By DONG Shuanglin, Aquaculture Ecology Laboratory, Fisheries College,
Ocean University of Qingdao, Qingdao 266003, P. R. China
dongsl@mail.ouqd.edu.cn

Abstract

Mariculture is an important industry, however, its rapid development has drawn much world attention to fish supplies and coastal environmental damage. Mariculture has two side effects on the coastal environment: some types of mariculture improve the coastal environment and increase food supply, but others deplete wild fisheries stocks and damage the coastal environment.
According to the driving factors of systems aquaculture ecosystems can be divided into two groups: a) autotrophic or natural trophic systems such as kelp culture system and raft culture system for scallops, which obtain energy from solar radiation and nutrients from water; b) heterotrophic or artificial trophic systems, such as net culture system for feeds- feeding fish and pond culture system for shrimp, which obtain energy mainly from artificial feeds. There are many features of ecological mutual compensation between the two types of aquaculture systems. Nowadays most mariculture production is produced from autotrophic systems in China. However, we should not neglect the negative effects of some types of mariculture on the coastal environment in our aim towards sustainable mariculture.
There are several ways to reduce mariculture pollution: structure optimization of single culture system or complex system, control of carrying capacity, treatment of discharge water and so on. Structure optimization of a single culture system selects cultured species among or between which there is mutualism in niche or in food resource utilization, though not a predatory or competitive relationship, determining the best culture forms, the best ratio and amount of cultured species in culture waters or culture systems. Structure optimization of complex systems is the compound or intercrop of ecologically compensational systems, that is, heterotrophic and autotrophic systems to reduce reverse effects of mariculture on the coastal environment, to improve the carrying capacity and ecological stability of mariculture systems, and to gain substantial commercial profit.