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Project ID:2006VI73B

Title: Diversity of freshwater fish and invertebrates of St. Thomas watersheds and its relationship to water quality as affected by residential and commercial development

Project Type: Research

Start Date: 03/01/2006

End Date: 03/28/2007

Congressional District: USVI

Focus Categories: Ecology, Water Quality, Education

Keywords: Guts, Watersheds, Water quality, freshwater fish, freshwater shrimps, Tropics

Principal Investigator: Nemeth, Donna

Federal Funds: $17,960

Non-Federal Matching Funds: 0

Abstract: St. Thomas, Virgin Islands, is characterized by steeply-sloped hillsides that channel waterflow after heavy rains in defined watersheds or "guts". Freshwater habitats, in the form of permanent streams or ponds, are very limited and in most guts water flow is rain-dependent, leaving small pools behind that are connected only during high flow conditions. The temporary nature of this freshwater habitat is threatened by encroaching human development, in the form of poorly regulated or nonexisitent sewage treatment, poor control of sedimentation from erosion, and discharge of industrial and household chemicals. Watershed research and the concept of "Ridge to Reef" or "Whitewater to Bluewater" has guided much research in determining how these anthropogenic factors affect marine life - yet in the Virgin Islands, there remains a large gap in knowing what organisms utilize this freshwater habitat, let alone an understanding of human impact on its biodiversity. This study proposes to test the following Null Hypothesis: There is no difference in aquatic faunal diversity between highly developed and undeveloped watersheds on St. Thomas. Six watersheds, varying in their level of human disturbance, will be surveyed for fish and crustacean diversity and standard water quality characteristics. One alternative hypothesis is that development may result in lower faunal diversity, as a result of negative impacts of higher levels of suspended sediment, sewage, and chemicals from road runoff and household/commercial discharge. The other alternative, that developed watersheds have higher faunal diversity, could reflect either a nutrient-limited system that benefits from high nutrient input to the ecosystem, or introduction of nonnative species (mosquitofish, Tilapia, or unwanted pets (red-eared sliders, DN pers. obs.). This proposed work will represent the first systematic documentation of aquatic fauna in St. Thomas guts, provide data that can guide management of the limited and fragile watershed habitat, and educate students and other island residents on the importance of understanding and protecting local ecosystems.

Progress/Completion Report, PDF

U.S. Department of the Interior, U.S. Geological Survey
Maintained by: John Schefter
Last Updated: Thursday, January 03, 2008
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