The influence of habitat and life history of reef fishes on the effectiveness of a Marine Protected Area network in Hawaii to replenish aquarium fish populations

A network of Marine Protected Areas (MPAs) on the west coast of the island of Hawaii (West Hawaii) has been shown to vary in its effectiveness to replenish depleted aquarium fish stocks. To determine the abundance and distribution of habitats needed to better design and manage MPAs in Hawaii, underwater video transects, remote sensing data, geographic information systems (GIS), and a benthic classification scheme were combined to develop a map of reef habitats previously identified as important to the life history of aquarium fish and other reef species. Using these maps, an assessment was conducted to quantify habitats used by different life stages of targeted aquarium fish species at four MPAs. Results showed that deep aggregate coral-rich areas and rubble substrates adjacent to shallow turf-rich boulder habitats at various depths (i.e., 0-30m) were used by all study species. In addition, appropriate habitat type for early life history stages of fish species, large areas of these habitats on the reef, and proximity of appropriate recruit, juvenile, and adult habitats were associated with an MPA showing effective replenishment. I further use landscape metrics to explore relationships between the most heavily collected aquarium fish species, yellow tang Zebrasoma flavescens, and the spatial characteristics of the reef in relation to the effectiveness of an MPA network in West Hawaii. Our results indicated that reef geomorphology, area and number of reef habitat types, and level of habitat complexity were associated with the significant recovery of aquarium fish populations. Furthermore, recruitment rate and years of closure influenced the effectiveness of the network, with more MPAs showing significant increases of yellow tang as years of protection increased and recruitment was consistent. My results demonstrate that the design of protected areas selected for conservation should take into account the recruitment dynamics and habitat requirements of each life stage of targeted species on spatial scales that are appropriate to the species being protected. The use of landscape metrics and new technologies, such as remote sensing and GIS, coupled with in situ population sampling can provide managers with the information required to select and manage reef systems for maximum benefit to targeted fish populations.