天津大神堂牡蛎礁保护区海域海水水质变化趋势分析与评价

本文根据2015－2020年6个航次的调查数据，对天津大神堂牡蛎礁海域海水温度、盐度、透明度、pH、溶解氧（DO）、溶解无机氮（DIN）、溶解无机磷（DIP）、化学需氧量（COD）、油类、重金属、悬浮物（SS）和叶绿素a（Chla）共18项水质指标进行分析，并通过营养状态指数（E）、营养状态质量指数（NQI）和综合污染...

Trend analysis and assessment of water quality for Dashentang Oyster Reef Marine Special Reserve in Tianjin

Based on the 6 investigation data of the Dashentang Oyster Reef Marine Special Reserve from 2015 to 2020, we analyzed 18 basic water quality indices, including water temperature, salinity, transparency, pH, dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), chemical oxygen demand (COD), oil, heavy metal content, suspended solids and chlorophyll a (Chl a), in addition to the evaluation of the eutrophication index (E), nutrient quality index (NQI) and Nemerow pollution index (P), in order to evaluate the quality of the oyster reef environment in this region. The results showed that the major exceeding standard factors were DIN, DIP, COD, oil and DO according to contribution rate from high to low. The degree of contamination and the main pollutants in seawater showed highly significant annual difference (P<0.001). The N/P ratio of seawater greatly changed from no nitrogen and phosphorus structure limitation to obvious phosphorus limitation. Chl a and primary productivity remained basically stable in this sea area.