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Notes
- Abstract:
- Cruise ship port activities are one of the largest potential sources of sediment resuspension in the marine environment of St. Thomas, United States Virgin Islands. The two cruise ship ports of St.Thomas were examined from September 2013 to May 2014 to better understand the extent of sediment resuspension and dispersal. To establish cruise ship effects on the water column a conductivity-temperature-depth (CTD) sensor package was used to collect water quality variables, including turbidity, on a daily basis directly before and after the passage of inbound cruise ships to each port. Water samples were taken simultaneously for total suspended solids (TSS) analyses. SedPods that mimic coral surfaces were deployed for one day at a time to determine deposition rates of particles in a transect running perpendicularly away from the ship docks for ship days and no ship days. Gross sediment accumulation rates were measured on a monthly basis by sediment traps at the same sites as SedPods. Analyses revealed that turbidity levels measured by the CTD did not differ before the arrival of ships and on days when there were no ships. Turbidity increased significantly directly after the passage of ships and increased with the number of ships present wit a significant interaction at the ships *before/after level (Friedman’s Rank, df-1, f-4.8642, p<0.0277). Turbidity was correlated with TSS values (R²=0.2983,p<0.0001) suggesting a similar effect of ship number and passage on TSS levels. The correlation was confirmed with a significant interaction at the ships *before/after level for TSS values (Friedman’s Rank, df=1,f=7.2857, p=0.0073). Sediment accumulation in sediment traps was greater closer to port (150 m) compared to farther away (550 m) (Friedman’s Rank, df=4, f=2.8675, p=0.0306). Sediment deposition on SedPods was not statistically different throughout the study, but trends of increasing deposition near port were observed. Results of this study serve as a baseline for knowledge on sediment resuspension and its dispersal in the cruise ship ports of St. Thomas. When compared to previous studies, current levels of sediment resuspension and particle fallout from cruise ships do not appear high enough to cause significant impacts on benthic habitats short term, but may cause damage to overall health in the long run.
- General Note:
- In the series University of the Virgin Islands Digital Collections.
Record Information
- Source Institution:
- University of the Virgin Islands
- Holding Location:
- University of the Virgin Islands
- Rights Management:
- Copyright Jennifer K. Kisabeth. Permission granted to the University of the Virgin Islands to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
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