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|Title:||Physical effects of beach nourishment on sea turtle nesting, Delray Beach, Florida|
The Discovery Center, Museum of Science, Art and History (Fort Lauderdale, Fla.)
Environmental Impact Research Program (U.S.)
United States. Army. Corps of Engineers. Jacksonville District.
Nelson, David A.
|Publisher:||Environmental Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical report (U.S. Army Engineer Waterways Experiment Station) ; EL-87-15.|
Abstract: A large percentage of all sea turtle nests in the United States are located in beaches that have been nourished or renourished. Questions have been raised about how physical changes in the beaches will affect the nesting activities of these sea turtles that use nourished beaches for nesting. This study was conducted to examine the physical changes in a beach from prior to nourishment in 1984 to after nourishment in 1985 at Delray Beach, Fla ., and the response of nesting turtles to those changes. Two beaches, one north and one south of the project area, were studied as references. Delray Beach had a harder consistency from both previous nourishments and the 1984 renourishment. The cause of the harder consistency is unclear. However, finer grain size, layering of sand grains, the cohesion of silt-clay particles, equipment operation on the beach, and weight of the sand-water slurry from the hydraulic pumping are probable contributors to a harder consistency. Effects of nourishment on nesting loggerhead turtles include: (1.) eggs and hatchlings were not affected negatively by the nourished sand; (2.) nest depth and frequency of false digs may be affected by the harder consistency, but this effect was not evident in this study; (3.) nest shape and nest digging time may be affected by sand consistency; (4.) the number of nests per emergence appears to have declined following the nourishment; (5.) aragonite sand may negatively affect piping hatchlings; and (6.) a scarp formed at Delray Beach and will form at most beaches. The scarp may block some turtles from nesting, while some may scale the scarp, particularly if the scarp is sloped.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Technical Report|