FINAL REPORT Characterization of benthic habitats and associated mesophotic coral reef communities at El Seco, southeast Vieques, Puerto Rico by: Jorge R. García-Sais, Jorge Sabater-Clavell, Rene Esteves, Jorge Capella, Milton Carlo P. O. Box 3424, Lajas, P. R.
[email protected] Submitted to: Caribbean Fishery Management Council San Juan, Puerto Rico August 2011 i I. Executive summary This research forms part of an initiative by the Caribbean Fishery Management Council (CFMC) to explore, map and provide quantitative and qualitative characterizations of benthic habitats and associated fish and shellfish communities present within the Caribbean EEZ, Puerto Rico and the USVI, with particular interest on shelf areas that have been seasonally closed to fishing in protection of fish spawning aggregations such as that of tiger grouper (Mycteroperca tigris) at “El Seco”, Vieques, Puerto Rico. The main objectives of the study included the construction of a georeferenced benthic habitat map of the mesophotic zone at “El Seco” within a depth range of 30 – 50 m, along with a quantitative, qualitative and photographic characterization of the predominant sessile-benthic, fish and motile-megabenthic invertebrate communities associated with these mesophotic habitats. Production of the benthic habitat map was based on a series of field observations and habitat classifications of the main reef topographic features by rebreather divers, as suggested from a multi-beam bathymetry footprint produced by the R/V Nancy Foster (NOAA). A total of 75 stations were occupied for direct field verification of benthic habitats, including 40 -10 m long transects for determinations of percent cover by sessile-benthic categories and 40 - 20 m long x 3 m wide belt-transects for quantification of demersal reef fishes and motile megabenthic invertebrates.