The Negative Effects of Beach Renourishment on Sea Turtle Nesting

What is a Sea Turtle? Sea turtle: A large air breathing reptile that spends most of it’s life in the water. It comes on land only if it is a nesting female, or if it is dead or dying.

Mating/Nesting What factors affect mating/nesting? What factors affect mating/nesting? Time of year that mating occurs- late spring to late summer Time of year that mating occurs- late spring to late summer Frequency of mating- most turtles mate every two to three years Frequency of mating- most turtles mate every two to three years Habitat that females choose to nest in Habitat that females choose to nest in

The Mating Process... Male and female turtle meet offshore to mate Male and female turtle meet offshore to mate Female then returns to the same beach that she was born to lay her clutch (eggs) Female then returns to the same beach that she was born to lay her clutch (eggs)

Nesting cont’d... Upon reaching the beach, the female drags her heavy body on shore Upon reaching the beach, the female drags her heavy body on shore She crawls to a point above the high water mark where she will then dig a body pit She crawls to a point above the high water mark where she will then dig a body pit

Nesting cont’d... Once body pit is dug female lays a clutch of about 100 eggs Once body pit is dug female lays a clutch of about 100 eggs Female then covers the eggs and leaves them to incubate and hatch, never to return to the site Female then covers the eggs and leaves them to incubate and hatch, never to return to the site

So What is the Problem? Beach Renourishment

Renourishment Beach renourishment is a solution to dealing with the rapid erosion of beaches Beach renourishment is a solution to dealing with the rapid erosion of beaches Sediment from an alternative source is brought in and placed on the existing shoreline to make it larger Sediment from an alternative source is brought in and placed on the existing shoreline to make it larger Renourishment is mostly done for economic reasons, such as attracting tourists to the beaches Renourishment is mostly done for economic reasons, such as attracting tourists to the beaches In Miami Beach renourishment increased beach attendance from 8 million in 1978 to 21 million in 1983 In Miami Beach renourishment increased beach attendance from 8 million in 1978 to 21 million in 1983

Problems with Renourishment If renourishment is done at the wrong time of the year (nesting season) it can cover nests If renourishment is done at the wrong time of the year (nesting season) it can cover nests Equipment can compact the sand or make trenches that the turtles cannot breach to get high enough above the water line Equipment can compact the sand or make trenches that the turtles cannot breach to get high enough above the water line Steep berms often form preventing females from nesting or causing them to nest below the high water mark Steep berms often form preventing females from nesting or causing them to nest below the high water mark

Problems with Renourishment Replaced sand is often harder (more resistant to shear) than the natural sand and it is usually not the same material Replaced sand is often harder (more resistant to shear) than the natural sand and it is usually not the same material Harder sand often results in a nest of inappropriate size or depth Harder sand often results in a nest of inappropriate size or depth More compact sand or sand of a different size can also results in insufficient gas exchange, change in nest temperature (important for determining turtles sex), and nest moisture More compact sand or sand of a different size can also results in insufficient gas exchange, change in nest temperature (important for determining turtles sex), and nest moisture

Regulate when renourishment is done Regulate when renourishment is done Require nest surveys, nest marking, and nest relocation Require nest surveys, nest marking, and nest relocation Modify methods to reduce compaction Modify methods to reduce compaction Renourish with sediment of similar grain size and composition Renourish with sediment of similar grain size and composition

Dealing with Renourishment- Nationally Because so little is known about sea turtles and their nesting behaviors it is important to protect them Because so little is known about sea turtles and their nesting behaviors it is important to protect them Federal Endangered Species Act Federal Endangered Species Act Section 7: Actions are not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of the critical habit Section 7: Actions are not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of the critical habit Section 9: prohibits the sale, import, export, or transport of any endangered species and most threatened species, and makes it unlawful to “take” them Section 9: prohibits the sale, import, export, or transport of any endangered species and most threatened species, and makes it unlawful to “take” them

Dealing with Renourishment- Locally Most states have their own laws and agencies dealing with protecting sea turtles Most states have their own laws and agencies dealing with protecting sea turtles Ex. Florida- FESA and Marine Turtle Protection Act Ex. Florida- FESA and Marine Turtle Protection Act Beach and coastal acts Beach and coastal acts Often require permits to be obtained for renourishment which allows authorities to regulate when it is done Often require permits to be obtained for renourishment which allows authorities to regulate when it is done

References cited Steinitz et al Beach Renourishment and Loggerhead Turtle Reproduction: A Seven Year Study at Jupiter Island, Florida. Journal of Coastal Research, 14:3, 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,