Population Connectivity And The Management Of Coastal Fisheries

No-take marine reserves are proposed as a conservation tool that may also benefit fisheries. I evaluated interactions among coastal ocean circulation processes, fish and invertebrate population dynamics and genetics, and fishery economics in order to identify emergent complexities and quantify potential benefits to fisheries from reserves. Stylized bioeconomic models demonstrate that reserves may benefit fisheries via export of larvae as long as the cost of fishing in between reserves is not exorbitant. However, such results are strongly influenced by the nature of the density dependent processes regulating recruitment of larvae at their settlement location. Oceanographic and genetic methods play an important role in the evaluation of fishery management because of their potential to detect and quantify variable patterns of connectivity among populations, and heterogeneity in connectivity patterns throughout a region may benefit fisheries when reserves are positioned correctly (e.g., in source locations). Oceanographic and genetic discontinuities detected across biogeographic and political barriers along the west coast of North America indicate minimal or sporadic connections, thus interdependency, between some sets of neighboring fishery regions. Within the Southern California Bight, complex patterns of connectivity within and among mainland and island populations detected via a coupled oceanographic-genetic approach suggest that reserve-based management may benefit fisheries there, and that oceanographic methods may be appropriate for determining optimal reserve locations in this region. A collective, spatially and temporally-explicit consideration of these ecological, oceanographic and economic dynamics is needed in southern California and throughout coastal marine areas to determine if and how reserves can help fisheries and managers achieve the twin goals of economic prosperity and ecological conservation within a single coastal marine ecosystem.