Identifying critical regions in small-world marine metapopulations

摘要

It can be difficult to mitigate the impacts of disturbances in nearshore marine systems. This is mainly because nearshore marine species occupy separate but connected subpopulations, with stress placed at one location, be it from overfishing or an oil spill, potentially being detrimental to stock levels at many other locations (1, 2). Understanding how this connectivity affects the whole metapopulation is crucial to our management of these systems. Here, we use detailed and realistic simulations of connectivity to identify the location of the most critical nearshore sites where protection from perturbation maximally reduces the risk of stock collapse. Specifically, using spatially explicit population modeling, we explore the structure of subpopulation connectivity for a range of nearshore species in the Southern California region. We find that these species live in small worlds, meaning that they are well connected by a small set of well-connected "hub" subpopulations. Using a metric from network theory, eigenvector centrality, we identify the location of these key hub subpopulations.