An Ecological Characterization of the Marine Resources of Vieques, Puerto Rico Part I: Historical Data Synthesis by Laurie J. Bauer, Charles Menza, Kimberly A. Foley, and Matthew S. Kendall NOAA/NOS/NCCOS/CCMA Biogeography Branch November 2008 NOAA Technical Memorandum NOS NCCOS 86 In Partnership with NOAA’s Office of Response and Restoration Mention of trade names or commercial products does not constitute endorsement or recommendation for their use by the United States Government. Citation: Bauer, L.J., C. Menza, K.A. Foley, and M.S. Kendall. 2008. An Ecological Characterization of the Marine Re- sources of Vieques, Puerto Rico. Part I: Historical Data Synthesis. Prepared by National Centers for Coastal Ocean Science (NCCOS) Biogeography Branch in cooperation with the Office of Response and Restoration. Silver Spring, MD. NOAA Technical Memorandum NOS NCCOS 86. 121 pp. An Ecological Characterization of the Marine Resources of Vieques, Puerto Rico Part I: Historical Data Synthesis Biogeography Branch Center for Coastal Monitoring and Assessment (CCMA) NOAA/NOS/National Centers for Coastal Ocean Science 1305 East-West Highway (SSMC-4, N/SCI 1) Silver Spring, MD 20910 NOAA Technical Memorandum NOS NCCOS 86 November 2008 Authors: Laurie J. Bauer Charles Menza Kimberly A. Foley Matthew S. Kendall United States Department National Oceanic and National Ocean Service of Commerce Atmospheric Administration Carlos M. Gutierrez Conrad C. Lautenbacher, Jr. John H. Dunnigan Secretary Administrator Administrator ABOUT THIS DOCUMENT This report is Part I of an ecological characterization of the marine resources of Vieques, Puerto Pico. The purpose of this work, conducted by CCMA’s Biogeography Branch in consultation with NOAA’s Office of Re- ponse and Restoration and other local and regional partners, is to provide resource managers and the people of Vieques with a synthesis of historical data and information on the marine ecology of Vieques, and to identify gaps where future research is needed. The report is divided into chapters based on the physical environment, habitat types, and major faunal groups. Part II of this assessment is a joint effort encompassing the work of CCMA’s Biogeography Branch and CC- MA’s Coastal and Oceanographic Assessment, Status and Trends (COAST) Branch. This work will build upon previous efforts by presenting new data on benthic habitats, assocated biological communities, nutrients, and contaminant concentrations in coral and sediments. Together, both components of the characterization will provide research and monitoring tools in order to support effective management and conservation of the island’s marine resources. Funding for this project was provided by NOAA’s Office of Response and Restoration, Coral Reef Conserva- tion Program, and Center for Coastal Monitoring and Assessment. For more information on this work and other Biogeography Branch projects, please see: http://ccma.nos.noaa.gov/about/biogeography/ and http://ccma.nos.noaa.gov/ecosystems/coralreef/vieques.html Direct questions or comments to: Mark E. Monaco, Ph.D. Biogeography Branch Lead National Oceanic and Atmospheric Administration 1305 East West Highway SSMC4, N/SCI-1 Silver Spring, MD 20910 Phone: (301) 713-3028 x160 p. i p. ii EXECUTIVE SUMMARY From the 1940s until 2003, portions of the island of Vieques, a municipality within the Commonwealth of Puerto Rico, were used by the US Navy as a base and training facil- ity, resulting in development and zoning history that differ in comparison to other Caribbean islands. The majority of former Navy lands are now under the jurisdiction of the De- partment of the Interior’s Fish and Wildlife Service as a Na- tional Wildlife Refuge, while a smaller percentage of land was transferred to the Vieques municipality and the Puerto Rico Conservation Trust. An analysis of the distribution and status of the marine resources is timely in light of the re- cent land transfer, increases in development and tourism, and potential changes in marine zoning around the island. To meet this need, NOAA’s Biogeography Branch, in coop- eration with the Office of Response and Restoration and other local and regional partners, conducted Part I of an ecological characterization to integrate historical data and research into a synthesis report. The overall objective of Image. Indigo hamlet (Hypoplectrus indigo) and other reef this report is to provide resource managers and residents fish. Photo: Biogeography Branch. a comprehensive characterization of the marine resources of Vieques to support research, monitoring, and manage- ment. For example, knowledge of the spatial distribution of physical features, habitats, and biological commu- nities is necessary to make an informed decision of the establishment and placement of a marine protected area (MPA). The report is divided into chapters based on the physical environment (e.g., climate, geology, bathymetry), habitat types (e.g., reefs and hardbottom, seagrasses, mangroves) and major faunal groups (e.g. fish, turtles, birds). Each section includes five subsections: an overview, description of the relevant literature, methods of analysis, information on the distribution, status and trends of the particular resource, and a discussion of eco- logical linkages with other components of the Vieques marine ecosystem and surrounding environment. The physical environment of Vieques is similar to other islands within the Greater Antilles chain, with some distinctions. The warm, tropical climate of Vieques, mediated by the northeasterly trade winds, is characterized by a dry season (December-April) and a rainy season (May-November), the latter of which is characterized by the occasional passage of tropical cyclones. Compared to mainland Puerto Rico, Vieques is characterized by lower elevation, less annual precipitation, and higher average temperatures. The amount of annual precipita- tion also varies spatially within Vieques, with the western portion of the island receiving higher amounts of rainfall than further east. While the North Equatorial Current dominates the circulation pattern in the Greater Antilles region, small scale current patterns specific to Vieques are not as well characterized. These physical processes are important factors mitigating the distribution and composition of marine benthic habitats around Vieques. In general, the topography of Vieques is characterized by rolling hills. Mt. Pirata, the tallest point at 301 m, is located near the southwest coast. In the absence of island wide sedimentation measurements, information on land cover, slope, precipitation, and soil type were used to estimate relative erosion potential and sediment delivery for each watershed. While slope and precipitation amount are the primary driving factors controlling runoff, land use practices such as urban development, military activity, road construction, and agriculture can increase the delivery of pollution and sediments to coastal waters. Due to the recent land transfer, increased development and tourism is expected, which may result in changes in the input of sediments to the coastal environment. North of Vieques, the bathymetry is generally uniform and shallow (<30 m), while the south and east coasts are characterized by a shelf slope dropoff that is closer to shore. The south coast includes numerous lagoons and embayments, including two bioluminescent bays (Puerto Ferro and Puerto Mosquito). Principal marine habitats around Vieques include coral reefs and hardbottom, submerged vegetation (sea- grass and algae), and mangroves. The most recent benthic habitat map of Vieques includes 72 km2 of mapped reef and hardbottom, about 80% of which is located offshore of former military areas. The south side of the island contains about twice the amount of mapped reef/hardbottom habitat as the north side. Recent surveys conducted offshore of civilian and former military areas have identified approximately 50 species of coral. Although long-term reef monitoring studies are lacking, there are indications that Vieques reefs have expe- rienced a decline in coral cover, especially Acropora sp., in recent decades. The effect of military activity on p. iii Vieques reefs has been subject to debate and the extent of damage from bombing and training purposes has not been thoroughly quantified. Other potential stresses to coral health include damage from hurricanes, coral bleaching, and diseases. The nearshore (within 3 nautical miles) waters of Vieques include ~116 km2 of mapped submerged aquatic vegetation habitat, approximately two-thirds of which is seagrass. The most extensive stretch of seagrass hab- itat is located in the shallow region along the north and northwest coasts and extends west to the main island of Puerto Rico. Additional seagrass areas are located in the bays, lagoons, and coastal areas on the south shore. Seagrass beds may include a mix of species Thalassia testudinum, Halodule wrightii, Syringodium filiforme, and Halophila decipiens and are usually intermixed with macroalgae. Mangrove forests are distributed throughout Vieques for a total of 4.4 km2. Locations with the largest areal cov- erage include lagoons on the northwest tip and the bays of the south coast, including the Bioluminescent Bays of Puerto Mosquito and Puerto Ferro. While comparisons with previous mapping efforts indicate that some areas have experienced a decline in mangrove coverage, overall losses appear to be less than in mainland Puerto Rico and elsewhere in the Caribbean. Anthropogenic threats to healthy