Marine Conservation Research Group, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
Sci Total Environ. 2024 Nov 20;952:175793. doi: 10.1016/j.scitotenv.2024.175793. Epub 2024 Aug 25.
Anthropogenic pressures such as climate change and nutrient pollution are causing rapid changes in the marine environment. The relative influence of drivers of change on the plankton community remains uncertain, and this uncertainty is limiting our understanding of sustainable levels of human pressures. Plankton are the primary energy resource in marine food webs and respond rapidly to environmental changes, representing useful indicators of shifts in ecosystem structure and function. Categorising plankton into broad groups with similar characteristics, known as "lifeforms", can be useful for understanding ecological patterns related to environmental change and for assessing the state of pelagic habitats in accordance with the EU Marine Strategy Framework Directive and the OSPAR Commission, which mandates protection of the North-East Atlantic. We analysed 29 years of Continuous Plankton Recorder data (1993-2021) from the North-East Atlantic to examine how trends in plankton lifeform abundance changed in relation to one another and across gradients of environmental change associated with human pressures. Random forest models predicted between 57 % and 80 % of the variability in lifeform abundance, based on data not used to train the models. Observed variability was mainly explained by trends in other lifeforms, with mainly positively correlated trends, indicating bottom-up control and/or shared responses to environmental variability were prevalent. Longitude, bathymetry, mixed layer depth, the nitrogen-to‑phosphorus ratio, and temperature were also significant predictors. However, contrasting influences of environmental drivers were detected. For example, small copepod abundance increased in warmer conditions whereas meroplankton, large copepods and fish larvae either decreased or were unchanged. Our findings highlight recent changes in stratification, reflected by variation in mixed layer depth, and imbalanced nutrient ratios are affecting multiple lifeforms, impacting the North-East Atlantic plankton community. To achieve environmental improvements in North-East Atlantic pelagic habitats, it is crucial that we continue to address climate change and reduce nutrient pollution.
人为压力，如气候变化和营养物污染，正在导致海洋环境的快速变化。驱动变化的因素对浮游生物群落的相对影响尚不确定，这种不确定性限制了我们对人类压力可持续水平的理解。浮游生物是海洋食物网中的主要能源资源，对环境变化迅速作出反应，是生态系统结构和功能变化的有用指标。将浮游生物划分为具有相似特征的广泛群体，即“生活型”，有助于理解与环境变化相关的生态模式，并根据欧盟海洋战略框架指令和 OS-PAR 委员会评估远洋栖息地的状况，该委员会授权保护东北大西洋。我们分析了来自东北大西洋的 29 年连续浮游生物记录器数据（1993-2021 年），以研究浮游生物生活型丰度的变化趋势如何相互关联，并与与人为压力相关的环境变化梯度相交叉。随机森林模型基于未用于训练模型的数据，预测了生活型丰度变化的 57%至 80%。观测到的变异性主要由其他生活型的趋势解释，主要呈正相关趋势，表明存在自上而下的控制和/或对环境变异性的共同响应，这是普遍存在的。经度、水深、混合层深度、氮磷比和温度也是重要的预测因子。然而，检测到环境驱动因素的影响是相反的。例如，在较温暖的条件下，小型桡足类的丰度增加，而浮游幼体、大型桡足类和鱼类幼体则减少或保持不变。我们的研究结果强调了最近的分层变化，这反映在混合层深度的变化上，以及不平衡的养分比正在影响多种生活型，从而影响东北大西洋浮游生物群落。为了实现东北大西洋远洋栖息地的环境改善，我们必须继续应对气候变化和减少营养物污染。
