蓬莱19-3溢油后莱州湾浮游植物群落结构

2012-2014年，对莱州湾浮游植物进行了9个航次调查，并同步监测其他环境因子。共鉴定浮游植物125种，隶属5大门类，以硅藻和甲藻为主，优势种主要为硅藻；浮游植物丰度和种类数均在8月达到最高值，多样性指数和丰富度指数年际变化趋势基本一致。春季(5月)浮游植物种类数与透明度呈显著负相关(P<0.01)，与COD呈显著正相关(P<0.01)；夏季(8月)与表层水温和无机氮呈显著负相关(P<0.01)；秋季(11月)浮游植物丰度与水深、盐度、溶解氧呈显著负相关(P<0.01)，与石油类呈显著正相关(P<0.01)。

The Structure of the Phytoplankton Community in the Laizhou Bay After the Oil Spills in Penglai 19-3 Oilfield

Ecosystems in the coastal water display high complexity and have been of great human and ecological interest. Interaction of physical, chemical and ecological factors determines the abundance and specific structures of biological communities, particularly the phytoplankton community, which comprise the lower levels of the oceanic food chain. To better understand the structure of the coastal phytoplankton community as well as its relationship with various environmental factors, a phytoplankton survey was carried out in the Laizhou Bay after the oil spills in Penglai 19-3 oilfield. At thirty-five selected sampling sites the water temperature, salinity, transparency, COD, pH, total nitrogen, and total phosphorus were investigated in May, August, and December from 2012 to 2014. Our sampling and testing methods followed the Specifications for Oceanographic Surveys and Specifications for Marine Monitoring. Correlation analysis (SPSS) was applied in determining the relationships between zooplankton communities and various environmental factors. Phytoplankton was collected using the standing net typeⅢ (mesh size 76μm, the standard sampling tool in Chinese marine phytoplankton studies) with a vertical haul at each grid station. Five classes including 125 species were commonly found in the surveyed area. Diatoms were the dominant species and dinoflagellates also shared importance in the phytoplankton community. Both the abundance and the diversity of phytoplankton reached the maximum in August, and the annual variation of diversity index and richness index tended to be consistent. The diversity of phytoplankton was positively correlated to the chemical oxygen consumption (COD,P<0.01) and negatively correlated to the transparency (P<0.01) in spring. There were negative correlations between the phytoplankton diversity and the surface temperature of seawater and inorganic nitrogen (P<0.01) in summer. As for the abundance of phytoplankton, it was negatively correlated to the depth of water, salinity, and dissolved oxygen (P<0.01) in autumn, and positively correlated to the petroleum content. These results showed that after the oil spilled, no obvious changes in the abundance and the community structure of the phytoplankton were present in the Laizhou Bay.