Marine community descriptions and maps of bays within the Virgin Islands National Park/Biosphere Reserve

Beets, James; Lewand, Lance; Zullo, Evonne

REPORT N0.2 Subtask 1.1 MARINE COMMUNITY DESCRIPTIONS AND MAPS OF BAYS WITHIN THE VIRGIN ISLANDS NATIONAL PARK/BIOSPHERE RESERVE A series of benthic maps were prepared representing the marine habitats of the bays of St. John. U.s. Virgin Islands. The maps were drafted from National Oceanographic Service aerial photographs and enhanced using existing photographs. charts and publications. All bays within Virgin Islands National Park boundaries were groundtruthed and described using standard methods adopted by the Virgin Islands Resource Management Cooperative. The major zones were identified and designated based on dominant physical and/or biotic components. A detailed description of major marine zones within each bay was prepared. Relative abundance. condition and percent cover of major species were estimated along with substrate composition and complexity. A summary of the marine zones and their relative condition within each bay and a list of general observations are presented. St. John and the surrounding small islands of the northern Virgin Islands are of volcanic origin with precipitous slopes ascending from the flat Puerto Rican platform. Typical of these steep, volcanic islands. St. John does not have an extensive bank barrier reef system. However. the complex topography of the island. cays and associated formations yield a great diversity of marine communities. Sedimentation, visitor damage, vessel anchor damage, beach erosion and illegal harvesting were noted problems within the Biosphere Reserve. Special emphasis was given to bays designated as 'areas of particular concern.' These areas of impact or potential impact were noted and described in greater detail. Two areas, Rawksnest and Fish Bays, were chosen for establishment of long-term phototransect monitoring. A review of methodologies used from mapping characterizing marine communities was prepared, emphasis was on efficient, cost-effective methods would be of practical use throughout the Caribbean.