Beach Nourishment Effects on Nesting

Marine Turtles

Whitney PyattNC Coastal Reserve & NERR

May 9, 2011

BackgroundBeach nourishment is the most widely used form

of stabilization and shoreline protectionImplications for nesting success of marine

turtles

Sediment QualityGrain size distribution

Beach morphology Shear resistance (hardness) Density Permeability Compaction

Sediment color Heat retention

Mineral content Aragonite v. Silicate Sand shape Heat retention

Rumbold et al., 2001

Rumbold et al., 2001

Brock et al., 2009

Brock et al., 2009

Research FindingsSteinitz 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.

Steinitz et al., 1998

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

Milton et al., 1997

Aragonite v. Silicate

Milton et al., 1997

ConclusionRenourishment effects vary spatially and

temporallyStudies show positive, negative, and neutral

effects on nest fateMost 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 Ecology 17(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 Caretta caretta (Loggerhead Sea Turtle) Nesting. Restoration Ecology 9(3), 304-310.

Speybroeck J. 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.