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Beach Nourishment Effects on Nesting Marine Turtles. Whitney P yatt NC Coastal Reserve & NERR May 9, 2011. Background. Beach nourishment is the most widely used form of stabilization and shoreline protection Implications for nesting success of marine turtles. Sediment Quality.
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Beach Nourishment Effects on Nesting Marine Turtles Whitney Pyatt NC Coastal Reserve & NERR May 9, 2011
Background • Beach nourishment is the most widely used form of stabilization and shoreline protection • Implications for nesting success of marine turtles
Sediment Quality • Grain size distribution • Beach morphology • Shear resistance (hardness) • Density • Permeability • Compaction • Sediment color • Heat retention • Mineral content • Aragonite v. Silicate • Sand shape • Heat retention
Research Findings Steinitz et al. • Nesting success: significantly lower on renourished than on the control beach both before, and for the two seasons after, the completion of a renourishment project. By the third season (year 2), no significant differences were evident. • Hardness: renourished sections were significantly greater than at the control section. 1 and 2 years after the project, shear resistance declined and became comparable to control site.
Research Findings • Emergence success at the renourished beaches (median of 71%) was lower than emergence success on the control beach (median of 78%), but the difference was not statistically significant. • Sands used as fill matched those on the control beach in size distribution and in bulk density. Steinitz et al., 1998
Aragonite v. Silicate Milton et al., 1997
Conclusion • Renourishment effects vary spatially and temporally • Studies show positive, negative, and neutral effects on nest fate • Most significant impacts appear to be 1-2 years postrenourishment
References • Brock, K. et al., (2009). The Effects of Artificial Beach Nourishment on Marine Turtles: Differences Between Loggerheads and Green Turtles. Restoration Ecology17(2), 297-307. • Milton, S. et al., (1997). The Effect of Beach Nourishment with Aragonite versus Silicate Sand on Beach Temperature and Loggerhead Sea Turtle Nesting Success. Journal of Coastal Research 13(3), 904-915. • Rumbold, D. et al., (2001). Estimating the Effect of Beach Nourishment on Carettacaretta (Loggerhead Sea Turtle) Nesting. Restoration Ecology 9(3), 304-310. • SpeybroeckJ. et al., (2006). Beach Nourishment: An Ecologically Sound Coastal Defence Alternative? A Review. Aquatic Conservation: Marine and Freshwater Ecosystems 16, 419-435. • Steinitz, M. et al., (1998). Beach Renourishment and Loggerhead Turtle Reproduction: A Seven Year Study at Jupiter Island, Florida. Journal of Coastal Research 14(3), 1000-1013.