Determining conservation potential of an opportunistically defined MPA boundary using fish telemetry

Abstract

Marine protected areas (MPA) that are created opportunistically must be evaluated in an ecological context to ensure that conservation goals and societal expectations are achievable. This study used acoustic telemetry to investigate movements of reef fish relative to the boundary of the Virgin Islands Coral Reef National Monument (VICRNM) in Coral Bay, U.S. Virgin Islands. Although created to enhance ecosystem protection, VICRNM boundaries were established purely on the basis of adjacency to public versus privately owned lands. Transmitters were implanted into a diversity of reef fish species representative of the local community whose movements were logged for one year on an array of acoustic-receivers that were positioned within, outside, and along the MPA boundary. Results indicate that the boundary has coincidentally aligned with a deep sandy area that does not cross through continuous reef or mangrove habitat. This acted as a natural barrier to movements of species such as Lutjanus griseus, Epinephelus guttatus, Cephalopholus cruentatus, Holocentrus rufus, and Sparisoma aurofrenatum. Other species were more mobile and were routinely detected outside VICRNM, especially at night, such as L. synagris, Haemulon plumierii, and H. sciurus. In addition to fish movements in relation to the VICRNM boundary, network analysis revealed several hotspots of concentrated fish activity including a reef promontory and bay mouths. Investment in enforcement of existing regulations to protect fish is warranted to realize the full potential of this MPA. Using these types of data, management actions in this and other MPAs can be focused on those species and locations that would experience the greatest benefit.