摘要
主要依据1991年5月—1995年11月和1997年2月—2004年11月连续多年每季度月(2、5、8、11月)采用“浅水Ⅲ型”浮游生物网在胶州湾10个站位自海底至表垂直拖取的浮游植物样品,同时搜集自1954年以来约50年有关胶州湾环境因子及浮游植物的历史监测资料,分析研究胶州湾环境因子长期变化及其对浮游植物群落结构的影响。结果表明,近50年来由于大规模人类活动给胶州湾环境带来很大影响,大量工农业生产废水和生活污水源源不断进入湾内,造成水域营养盐含量迅速增加,近3年来NO3-N和NH4-N比1962年分别提高14.5倍和9.5倍,沿岸带的开发导致胶州湾水域面积不断缩小,纳潮量下降,水域环境容量和自净能力减弱,水域环境趋向退化。环境因子的变化对胶州湾浮游植物群落结构造成明显的影响,近50年来,浮游植物数量呈增加趋势;优势种更替明显,原先一些优势种不再居优势地位,而比较喜肥的种类如中肋骨条藻数量显著增加,成为最重要的优势种;浮游植物多样性指数有所下降,表明胶州湾浮游植物群落处于演化之中,同时由于营养盐含量迅速增加,为赤潮的形成与发展提供了丰富的物质基础,自1997年以来,赤潮几乎连年暴发,并有愈演愈烈的发展趋势,反映出胶州湾生态环境已呈现异常的征兆。
Long-term variation of environmental factors and their influences on phytoplankton were revealed by data obtained in 51 quarterly cruises （February, May, August and November） during 1991-2004 in Jiaozhou Bay combined with the historical data over the past 50 years. Phytoplankton were sampled with nets （37cm diameter, 140cm length, 77μm mesh） from bottom to surface for subsequent counting of cell number under microscope. Jiaozhou Bay is a semi-enclosed bay situated in the western part of Shandong peninsula, China, which is sur- rounded by Qingdao City, with an area of about 390 km2 and an average water depth of about 7m. The bay mouth is narrow, only about 2.5 km wide. The distribution of phytoplankton that characterized by dense area appeared mainly in northeastern and northwestern parts near-shore area, and in the middle and southern parts, the density was low. The phytoplankton abundance was higher inside the bay than outside the bay. Clear seasonal variation of phytoplankton was shown. The peak in phytoplankton abundance occurred frequently in winter and summer; and the trough value occurred mainly in autumn. Human activities have greatly impacted the environment of Jiaozhou Bay. Large amount of industrial and residential wastewater concentrated with N, P and organic matters discharged into the bay every day. Large-scale maricultures of filter-feeding bivalve, fish and so on have caused serious ecological problems in the bay. Nutrient concentrations had been continuously rising since 1960s. NO3-N, NHa-N and POa-P were doubled by 7.26, 5.10 and 2.43 times from 1960s to 1990s, respectively. The mean contents of these nutrients in 2001-2003 were obviously higher than that in 1990s. Significant long-term environmental changes have affected the succession of phytoplankton community constructure. The phytoplankton species composition, abundance and dominant species have also experienced obvious variation since 1954. Dominant species have considerably alternated. Some species such as Chaetoceros affinis, Thalassionema nitzschioides, Rhizosolenia setigera, Coscinodiscus radiacus have been replaced by Asterionella kariana, Thalassiosira nordenskioldi, Nitzschia paradoxa and so on. Some eutrophic species such as Skeletonema costatum and a warm water species Lithodesmium undulatum increased abundantly. The phytoplankton diversity index （Shannon＇s H＇） has slightly decreased during past 50 years. From 1977 to present, red tide events have been increasing in number, frequency and intensity in Jiaozhou Bay. Marine eutrophication is widely believed to be the major cause of red tide.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2005年第6期487-498,共12页
Oceanologia Et Limnologia Sinica
基金
中国科学院知识创新项目
KZCX3-SW-214号。
关键词
胶州湾
环境变化
浮游植物
群落结构
Jiaozhou Bay, Environmental change, Phytoplankton, Community structure
