Water Resources Research Act Program

Details for Project ID 2010VI170B

MEASUREMENT OF PARTICULATE ORGANIC MATERIAL AND EROSION RATES IN SMALL SUBTROPICAL WATERSHEDS ON THE EAST END OF ST. CROIX, USVI

Institute: Virgin Islands
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-01
Total Federal Funds: $20,294 Total Non-Federal Funds: Not available

Principal Investigators: Bernard Castillo, Carlos Ramos-Scharron, Kynoch Reale-Munroe

Project Summary: Increased sedimentation in near shore coastal habitats resulting from anthropogenic activities continues to be one of the main stressors threatening near shore habitats throughout the US Virgin Islands. Current research is underway in the US Virgin Islands in an effort to better understand the relationships between increased terrestrial sediment inputs and the degradation of receiving marine ecosystems. Specific objectives included in the current research are 1.) to quantify the impact of anthropogenic activities in increasing sediment; and 2.) to asses relationships between terrestrial sediment input and marine conditions. This research focuses on net sediment yields and does not partition those yields into organic and inorganic components. The transport of particulate organic matter is important in understanding threats of eutrophication by increased loading of organic material into the bays. An extensive field study, located in the small watershed of the East End Bay in St. Croix is designed to quantify and compare terrestrial sediment inputs into the downstream receiving waters from natural areas and from disturbances due to trail installation and usage. Currently, sixteen silt fences and a tipping bucket rain gauge are installed at the study site. The scope of this proposal is to broaden the study area by adding four additional silt fences and an additional rain gauge in Isaacs Bay, which will allow for more intensive sediment sampling and to quantify the transport of particulate organic matter. Subsamples taken from the total sediment yield samples will be sieved to determine particle-size distribution and analyzed for organic content, using the Loss on Organic method. Given that studies are currently underway in the East End Bay watershed in St. Croix regarding sediment loading in near shore marine environments, additional funds to supplement that effort would provide a missing link to better understand the relationships between terrestrial sediment inputs and coastal habitat conditions. Thereby the specific proposed objectives are (1) to quantify particulate organic material present in sediment samples collected from all sediment traps in East End Bay and Isaacs Bay and (2) to quantify the effects that land disturbance, in the form of a foot trail, affects the production of organic material by surface erosion.