Abstract: Marine reserves are an important tool for biodiversity conservation, but they are often relied upon also to benefit fisheries, particularly in tropical coastal areas. However, the fishery implications of decisions on the size, location and combined coverage of reserves within a network are generally unspecified. In this seminar, I will present findings from an ongoing ARC Linkage project, which aims to advance marine reserve network design theory for fisheries by identifying circumstances under which the long-term productivity on fishing grounds is either increased or at least not diminished. Most of this work is model-based and focused on benefiting fisheries that are diverse, unassessed and otherwise unregulated. Our findings suggest that realistic reserve network designs (10-30% protection of fished habitat based on reserves with a mean diameter of 1-10 km) should benefit the long-term productivity of almost any such complex fishery. Reliable information on (1) the scale of adult movements and larval dispersal, and on (2) environmental heterogeneity for systematic reserve placement, can be important to optimize reserve targets within and beyond these ranges. Without such information, 20-30% protection of fished habitat based on reserves with a maximum diameter of 15 km should help ensure that long-term fisheries productivity is not diminished even if overfishing is not yet a problem, while providing a much higher potential for efficient species protection and fisheries rebuilding than 10-20% protection based on small reserves whenever fish populations are already substantially depleted. This generic finding is informed by empirical data that include previously unavailable measurements of fish movements as both adults and larvae on coral reefs. Thus, our project encourages a more aggressive than currently targeted use of reserves where both biodiversity conservation and higher fisheries productivity are most urgently needed.

Bio: Nils is a postdoc at the University of Queensland. He is broadly interested in marine ecology, fisheries and conservation science, focusing primarily on fish population dynamics and spatial fisheries management. Nils has been using a range of methods, including field surveys, laboratory experiments, population genetics and modelling, to address research questions in these fields. His current work in Professor Peter Mumby’s Marine Spatial Ecology Lab aims to support decisions on marine reserve network designs that can benefit both conservation and fisheries in the Coral Triangle region, specifically Indonesia and the Philippines.