Potential Fisheries Impact of Ballast Water Uptake from Liquefied Nautral Gas Vessels at the Southern LNG EL Paso, Elba Island Facility in Savannah, Georgia

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Thompson, Randi Tyler
Department of Marine Sciences
Ballast Water
Ecological Impact
Elba Island
Savannah River
Discharge of ballast water
Ecological Disturbances
Environmental Impact Analysis
Issue Date
Other Titles
Randi Tyler Greer Thompson
Southern Liquefied Natural Gas (SLNG) vessels offload their cargo of liquefied natural gas (LNG) at the SLNG-El Paso, Elba Island Facility in Savannah, Georgia. The vessels are required to withdraw 11.3 to 25.6 millions of gallons of Savannah River water as ballast at the SLNG-El Paso berthing slip prior to leaving port to maintain vessel stability. The purpose of this study was to determine if cumulative water uptake would have any impacts on local fisheries by removing fish, crab, or shrimp eggs, larvae, and/or juvenile stages from the river. Ballast water uptake was simulated on site at the Elba Island facility and entrained organisms were collected using a 200 μm mesh plankton net. Taxa were identified and analyzed for seasonal, tidal, and night/day differences. Seasonal and tidal phase differences were tested with a nonparametric Kruskal-Wallis One-Way ANOVA on Ranks, and all pairwise multiple comparisons were made using Dunn’s Method. T-tests were performed for night and day data. Nine taxa of fish and nine invertebrate taxa were collected, but only three of these were somewhat commercially important and none were endangered or threatened. Fiddler crabs (n = 6,797) and mysids (n = 5,659) were the most abundant species in samples. Seasonal differences in abundance were the most common differences observed in this study with warmer months in having more organisms entrained. Crab larvae were also commonly more abundant at night. The LNG carriers could reduce fiddler crab entrainment by 96% and mud crab entrainment by 92% by avoiding night ballasting during summer months July-September. Fish entrainment could be reduced if ballasting was minimized to the maximum extent possible from February to May.