Lindegren Martin, Andersen Ken H, Casini Michele, Neuenfeldt Stefan
Ecol Appl. 2014;24(7):1820-32. doi: 10.1890/13-0566.1.
The degree to which metapopulation processes influence fish stock dynamics is a largely unresolved issue in marine science and management, especially for highly mobile species such as Atlantic cod (Gadus morhua) and herring (Clupea harengus). The Baltic Sea comprises a heterogeneous oceanographic environment that structures the spatial and temporal distribution of the dominant species cod, herring, and sprat (Sprattus sprattus). Despite local differences, the stocks are traditionally managed as homogeneous units. Here, we present a metacommunity-perspective on source–sink dynamics of Baltic Sea fish stocks by using a spatially disaggregated statistical food web model. The model is fitted to area-specific time series of multiple abiotic and biotic variables using state-space methods. Our analysis reveals pronounced net fluxes between areas, indicative of source–sink dynamics, as well as area-specific differences in species interactions (i.e., density dependence, competition, and predator–prey) and the degree of fishing and climate impact on survival and recruitment. Furthermore, model simulations show that decreasing exploitation pressure in the source area for cod (without reallocating fishing effort) produces an increase in neighboring sink habitats, but a decline of prey species in response to increased predation. Our approach provides valuable insight concerning metacommunity-structuring of marine fish and may serve as an important tool for implementing sustainable management strategies under the ecosystem approach to marine and fisheries management.
集合种群过程对鱼类种群动态的影响程度，在海洋科学和管理领域很大程度上仍是一个未解决的问题，特别是对于像大西洋鳕鱼（Gadus morhua）和鲱鱼（Clupea harengus）这样高度洄游的物种。波罗的海拥有一个异质的海洋学环境，它构建了优势物种鳕鱼、鲱鱼和黍鲱（Sprattus sprattus）的时空分布。尽管存在局部差异，但这些种群传统上被作为同质单元进行管理。在此，我们通过使用一个空间离散的统计食物网模型，提出了一个关于波罗的海鱼类种群源 - 汇动态的集合群落视角。该模型使用状态空间方法拟合到多个非生物和生物变量的特定区域时间序列。我们的分析揭示了各区域之间明显的净通量，这表明了源 - 汇动态，以及物种相互作用（即密度依赖、竞争和捕食 - 被捕食）的区域特定差异，以及捕捞和气候对生存和补充的影响程度。此外，模型模拟表明，在鳕鱼的源区降低捕捞压力（不重新分配捕捞努力）会导致相邻汇生境增加，但由于捕食增加，猎物物种数量会减少。我们的方法为海洋鱼类的集合群落结构提供了有价值的见解，并可能成为在海洋和渔业管理的生态系统方法下实施可持续管理策略的重要工具。
