珠江口海域污染的水质综合污染指数和生物多样性指数评价

利用水质综合污染指数和生物多样性指数分别对珠江口海域2006年7月和2007年3月调查的数据进行污染程度评价, 并讨论利用多样性指数评价的合理性。结果表明珠江口海域的污染等级处于中度污染至严重污染之间, 其中利用水质化学因子进行综合评价的结果为严重污染, 利用生物多样性指数进行评价的结果为轻中污染至重污染。本研究认为利用浮游动物多样性指数评价海域水质污染程度比利用浮游植物或底栖生物的多样性指数评价海域水质污染程度更加合理, 但其评价标准仍有待更多的调查来验证和修正。同时, 利用不同类群生物的多样性指数对海洋水质与生态环境质量进行评价有时会存在一定差异。因此在实际评价中不能单从一种指数结果就轻易下定论, 结合理化监测结果, 才能得到符合实际的结论。

Assessment of the Pearl River Estuary pollution by water comprehensive pollution index and biodiversity index

Two cruises were carried out to investigate the water quality and ecological status in the Pearl River Estuary in July 2006 and March 2007. Water comprehensive pollution index and biodiversity index (including phytoplankton, zooplankton and benthos) were used to assess the pollution status. In addition, rationality of the assessment by using the biodiversity index was also discussed. The results indicated that the pollution degrees of the Pearl River Estuary were between moderate to severe. Water comprehensive pollution index showed that it was at a severely polluted status both in wet and dry seasons. Biodiversity index led to different results, which varied from lightly-moderate pollution to severe pollution. Among the three biodiversity indices, we considered that zooplankton diversity index was more congruent than the other two indices in pollution status assessment. However, the evaluation criteria should be verified and modified in future study. It was concluded that assessment for the environment quality and ecological status by using different biodiversity indices may come to a varied result, and a simple conclusion could not be hastily educed but should be associated with physicochemical factors.