Mans long-term impact on sedimentation: Evidence from salt pond deposits
Nichols MM and Brush GS. 1988. Mans long-term impact on sedimentation: Evidence from salt pond deposits. Biosphere Reserve Research Report No. 23. National Park Service and Virgin Islands Resource Management Cooperative
Coastal ecosystems of the Virgin Islands Biosphere Reserve, St. John, are subject to stress of sedimentation from watershed erosion, both natural and man-induced. A pilot study was initiated at Mandal Pond and Reef Bay mangrove swamp on the southern coast of St. John to determine sedimentation rates and to discover if the rates have changed in response to man's historical activity in the watershed. The results reveal the deposits are ordered in time, display horizons and preserve components produced in the pond/swamp or derived from the watershed. Radiocarbon ages of intertidal peat indicate that both sites have submerged at a uniform rate of 0.08 em/yr. Submergence exceeds sediment infilling at Mandal Pond whereas infilling exceeds submergence at Reef Bay. Consequently, the swamp size at Reef Bay and water depth decrease with time, depositional units change and watershed-derived alluvium encroaches on the swamp. Despite man's activity, no massive effect of sedimentation on the swamp is observed. Man's effects are relatively small in comparison to the long-term natural evolution of the system.
- Type
- Published Report
- Authors
- Nichols, Maynard; Brush, Grace
- Date of Issue
- 1988-09
- Publisher
- National Park Service and Virgin Islands Resource Management Cooperative
- Units
- VIIS
- Keywords
- Human Impact, Isotopic Dating, Physical Sciences, Pollen, Sediment Stratigraphy, Sedimentation, St. John US Virgin Islands