The Effects of Marine Reserves on Regional Groundfish Diversity within the San Juan Archipelago, Washington

Groundfish populations in the greater Puget Sound region have experienced intense declines as a result of past commercial and recreational fisheries. Mitigation efforts have included harvest limitations, fishery closures, and the utilization of Marine Protected Areas such as marine reserves. To investigates the regional effects of established marine reserves on the groundfish biodiversity, fishery-independent data from the Washington Department of Fish and Wildlife’s groundfish surveys were used to analyze temporal and spatial variations in mean diversity levels for three species groups: Gadidae, Hexagrammidae, and Sebastes. Efforts to determine species groups that benefit from the existing marine reserves showed that Sebastes and Hexagrammidae, normally associated with complex rocky substrate, significantly prefer habitat of that type, suggesting that current marine reserves are appropriately located for these targeted species. Further spatial analysis showed significant groupings of high and low diversity sampled sites throughout the region. Temporal variations in mean diversity values for each sampled year were also observed, however the cause of these fluctuation in diversity values could not be determined by this study. Results from this study highlight the need to monitor ecosystems where marine reserves have been established, to gain a better understanding of their regional influence on groundfish species.