渤海湾海河口区浮游植物动态及其与有机污染的关系

近二十年来，随着海洋环境科学的发展，河口污染和生态问题日益受到重视。关于污水排放对河口内湾浮游植物生态的影响，近年Ketchum, B. H. (1967); McCormick, J.M. 等(1975); Rice, T. R. (1975); Jenkins, S. H. (1978); Thompson, G. B. 等(1981 ); Meyers, V. B. 等(1983)和Joint, I. R.(1984)都做过调查研究和评论。但迄今国内有关这方面的研究报道甚少。海河口是一个有污染源的生态环境特殊的感潮河口，受自然因素和人类活动的影响很大。由于其地理位置得天独厚，水质肥沃，饵料丰富，历来是许多经济鱼虾类优良的天然产卵、索饵和肥育的场所，在渤海渔业上占有重要位置。但近十多年，由于入海径流量锐减和城市污水排海总量的增加1)，其水质逐渐恶化，环境正由半咸水向海洋化方向演变，对河口渔业构成严重威胁。对此，我所曾于1978-1981年对渤海湾的污染状况及影响进行过多学科的综合调查，在渤海湾污染的浮游植物生态效应、海湾富营养化及其与赤潮的关系等方面，也做过初步研究(邹景忠等，1983; 1984; 1985 )。当时由于受调查范围和项目的限制，对河口有机污染及生态效应的研究还很不够，所获得的一些资料尚不足以作出定量的科学论断。本文着重探讨海河口区浮游植物的生态变化及其与有机污染的关系，旨在为综合分析和评价海河口区目前的生态质量及演变趋势，为河口环境的综合整治提供科学依据。

PHYTOPLANKTON KINETlCS OF THE HAIHE ESTUARINE AREA AND ITS INTERRELATION WITH ORGANIC POLLUTION

A study was carried out in 1983-1985 on the relationship between phytoplankton (species diversity index, standing crop and primary production) ecological changes and organic pollution in the Haihe estuarine area. The materials for this study were collected in May, August and October, (presenting the periods of minimum, maximum and average river runoff, respectively) from a total of 29 stations, 6 of which were located in Yongdingxin River influenced by tide and in the mouth of wastewater river.A total of 60 species of phytoplankton were found in the investigated area. The ccotype were essentiality eurytopic species and neritic. The distribution of phytoplankton exhibits marked regional and seasonal variations. The species diversity values, the standing crop of phytoplankton and primary production were much higher in the outer estuary than in the inner estuary, and showed marked increase from inner estuary towards the outer estuary. The highest values often occur in the area where fresh-sewage water and seawater mix with each other. The total number of phytoplankton cell were greater in October and smaller in August. And chlorophyll-a contents were greater in August and smaller in October.Environmental factors which affect phytoplankton ecological changes of the Haihe estuarine area are referred to as light intensity, nutrients concentration, temperature, salinity, turbidity and other factors. Although it is difficult to determine the relative importance of individual factors, sewage-related pollution appears to have played a major role in bringing about the ecological changes of the Haihe esturine phytoplankton. In the polluted inner estuary and near senage outfall sites, net phytoplankton diversity valaes were significantly reduced, and the cell density and primary production were significantly lower, too. A negative correlation exists between the diversity values, cell density and COD, BOD5, TON, TOP and TOC concentration. Chlorophyll-a has no significant positivity correlated with these pollutants. Obviously, the decrease in the diversity values and the number of phytoplankton cell in inner estuary are due to the influences of organic pollution. However, this effect is rather small in the outer estuary, occurring only in August.