Cooperative Multiagency Reef Fish Monitoring Protocol for the U.S. Virgin Islands Coral Reef Ecosystem, v. 1.00 Natural Resource Report .

摘要

Reef fish populations are an essential component of the United States Virgin Islands (USVI) coral reef ecosystem and are of great economic, ecological and cultural importance to the region. Yet, striking population and community level declines have been observed over the past several decades due to intensive exploitation and systemic degradation of essential habitats. This protocol entitled 'Cooperative Multiagency Reef Fish Monitoring Protocol for the U.S. Virgin Islands Coral Reef Ecosystem' provides the necessary technical background and detailed description of key methods for monitoring and assessment of reef fish populations throughout the USVI. The objective of this protocol is to determine the status, trends, and variability of reef fish species populations and communities within hard-bottom habitats at dive-able depths within the U.S. Virgin Islands and Puerto Rico regions, specific sub-regions (e.g., St. Croix, St. John/Thomas), and inside vs. outside different management zones (e.g., national and territorial parks, monuments, and reserves) using measures including abundance, density, occupancy, spatial distribution, size structure, species richness, and community composition. Special attention is paid to specific exploited and ecologically important reef fish species. A probabilistic stratified random sampling design is used as the central statistical method for collecting size-structured abundance data for USVI reef fishes from a finite sample frame of grid cells classified by habitat and depth. Field methods consist of a 25m x 4m linear belt reef fish visual survey in which reef fish species are counted and measured. The resulting quantitative metrics (e.g., density, abundance, occupancy) allow multispecies assessments in a large-scale geographic or ecosystem context as well as within managed areas.