Changes in phytoplankton communities due to anthropogenic nutrient load and climate change often lead to eutrophication and harmful algal blooms that can affect biogeochemical cycling. However, little is known about the specific responses of various species to environmental variables. 17-year long data on the midsummer phytoplankton biomass in the Neva Estuary were analyzed to show the changes in the composition of phytoplankton in relation to water depth, transparence, salinity, temperature, concentrations of total phosphorus and chlorophyll a, and plankton primary production. One hundred seventy-four species and forms from eight taxonomic classes were found in phytoplankton. Fifteen species were potentially harmful. The most diverse and abundant groups were cyanobacteria, green algae and diatoms. Canonical Correspondence Analysis showed that the biomass of various species from each phytoplankton group correlated differently with environmental factors. However, within each group, there were some predominant trends in the correlative response to changes in environmental variables. The biomass of cyanobacteria was high in the middle and lower reaches of the estuary and, in general, positively correlated with water salinity. The biomass of most species of green algae and diatoms correlated negatively with it. These algae showed a positive trend in biomass in the upper and middle reaches of the estuary during the last decades that may be explained by changes in weather conditions. Taking into account that climate models predict future increases in precipitation and temperature in the northern Baltic, the future expansion of freshwater phytoplankton species in estuaries of the northern Baltic Sea is very likely.

由于人为养分负荷和气候变化导致的浮游植物群落变化，通常会导致富营养化和有害藻华，从而影响生物地球化学循环。但是，关于各种物种对环境变量的具体反应知之甚少。分析了涅瓦河河口盛夏浮游植物生物量的17年长期数据，显示了浮游植物组成与水深，透明度，盐度，温度，总磷和叶绿素a的含量有关的变化。和浮游生物的初级生产。在浮游植物中发现了来自八个分类学类别的一百七十四个物种和形式。十五种潜在有害。种类最多，种类最多的是蓝细菌，绿藻和硅藻。典范对应分析表明，每个浮游植物群中各种物种的生物量与环境因素的相关性不同。但是，在每个组中，对环境变量变化的相关响应中都有一些主要趋势。蓝藻的生物量在河口中下游较高，通常与水盐度呈正相关。大多数绿藻和硅藻的生物量与其负相关。在过去的几十年中，这些藻类在河口上游和中游的生物量呈现出积极的趋势，这可以用天气状况的变化来解释。考虑到气候模型预测了未来波罗的海北部地区降水和温度的增加，未来很有可能在波罗的海北部河口增加淡水浮游植物的种类。