* FEI X.G. and C.K. Tseng, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, CHINA
e-mails: fei@ms.qdio.ac.cn & fei@public.qd..sd.cn: Fax: 86 532 2873244 & 2880645

Abstract

Eutrophication is a serious problem of coastal waters in many part of the world. Elevated nutrients are suggested to induces phytoplankton blooms, including "Red Tide" phenomenon.. This may be followed by heavy losses in areas of extensive aquaculture. Some cultivated seaweeds have very high productivity roles and are thus able to absorb large quantities of N, P and CO₂ , whilst also producing large amount of O₂ and so doing have an excellent effect on decreasing eutrophication. The author believes that large scale seaweed cultivation could provide good solution to the eutrophication problem in certain coastal waters. To put this idea into practice, four critaria should be addressed. (a) Large-scale cultivation could be undertakened. (b). Science and technology problems for cultivation have been fundamentally solved. (c). No harmful ecological effects could be experienced due to the cultivation. (d) Cultivation must be economically feasible and profitable.

For a number of years, the large-scale cultivation of Laminaria japonica has been encouraged in order to balance the negative effect from scallop cultivation in Northern China. Basic research has been conducted in South China in recent years and has shown that Gracilaria lemaneaformis, and Porphyra haitanensis are the two best candidates to be grown in order to reduce eutrophication along the Chinese southern coast, from Fujian to Guangdong, Guangxi and Hong Kong.