Characterization of nekton assemblages associated with seagrasses within the newly-established Research Natural Area and adjacent open-use zones at Dry Tortugas National Park
   Theodore Switzer, Fish and Wildlife Research Institute

Abstract: Florida’s CWCS had identified the need for information on the distribution and abundance of numerous species of greatest conservation need (SGCN), especially in terms of the quantity and quality of habitats of special concern. The proposed project is designed to fill acknowledged data gaps by providing information regarding nekton assemblages associated with seagrasses within Dry Tortugas National Park (DRTO). The primary objective of the proposed study is to characterize community structure of seagrass-associated nekton within the DRTO Research Natural Area (RNA) and adjacent open-use areas, especially in terms of habitat use by species of greatest conservation need. A secondary objective is to provide baseline data from which long-term changes in community structure in association with the establishment of the DRTO RNA can be compared. The proposed project will be the first comprehensive assessment of seagrass-associated nekton assemblages in DRTO. Accordingly, it will enhance our understanding of the distribution and abundance of a variety of understudied species of greatest conservation need. Additionally, the integration of project results with ongoing research activities within DRTO will provide important insight into ecosystem effects of the establishment of marine protected areas, as well as further the development of ecosystem-based management of reef resources in Florida. Seasonal (spring and fall) stratified-random surveys of nekton assemblages associated with seagrass habitat will be conducted using 21.3-m center bag seines in shallow areas (< 1.5 m) and 6.1-m otter trawls in deeper areas (< 7.6 m). During each season a minimum of thirty seine samples and ten trawl samples will be collected; these samples will be equally partitioned between the DRTO RNA and adjacent open-use areas. Additionally, during the first season (Fall 2008) a complimentary visual census of reef fish resources will be conducted to determine the relative effectiveness of visual surveys and trawls to characterize seagrass-associated nekton assemblages. At the completion of the proposed project, a comprehensive suite of statistical analyses and modeling efforts will be conducted to evaluate seagrass assemblages within the DRTO RNA and adjacent open-use areas as well as examine overall ecosystem structure and function within the greater Tortugas region.

Award Matching Funds Total
$135,081.00 $135,081.00 $270,162.00

Year Funded Starting Date Ending Date
2007 7/1/2008 6/30/2010

Location: Monroe County