Nicholas School Internship Blogs

Sea Turtles vs. Sea Walls
by -- July 19th, 2016

Dotted across the summertime shores of South Carolina are numerous sea turtle nests. Predominately these nests are of the threatened Loggerhead sea turtle (Caretta caretta), the state reptile of SC. With protections like sea turtle excluder devices and the threatened status of the species, there has been an encouraging increase in nests over recent years. However, as briefly touched up on my first blog, in the face of beach erosion and its threat to homes, there is a developing controversy between the protection of home owner’s property and Loggerhead nesting.

One of the first Loggerhead hatchlings of the season.

One of the first Loggerhead hatchlings of the season.

 

To help protect beach front home owners from losing their properties to the rising sea, there has been new research into a product called a “wave dissipation device.” These experimental structures have been constructed in front of a number of homes along the beaches of Isle of Palms in Charleston and Harbor Island in Beaufort County. The structures are meant to act like sea walls, which protect the properties from the harsh effects of wave energy, but unlike sea walls they actually allow water through the structure. Due to the diffusion like mechanics of the devices and the “Lincoln Log” like manner in which they are constructed, the walls are meant to be a flexible and temporary solution to shoreline change.

Wave Dissipation Device as the tide is going out.

Wave Dissipation Device as the tide is going out.

 

Wave Dissipation Device at High Tide.

Wave Dissipation Device at High Tide.

Recently turtle patrol volunteers, groups of citizens organized to roam South Carolina beaches to monitor sea turtle nests, have been seeing false crawls due to the presence of the wave dissipation devices. False crawls occur when a female crawls up the beach to lay her nest, approaches some kind of structure, and turns around without depositing her nest. The issue with false crawls, especially when it comes to a threatened species, is that females only have a few opportunities a season to lay their nest. If a female doesn’t get that opportunity, due to false crawls or another interference, her eggs will be released out at sea and never produce.

DNR Labeled Sea Turtle Nest. This nest has likely be the victim of predation.

DNR Labeled Sea Turtle Nest. This nest has likely be the victim of predation.

With evidence of these false crawls in front of wave dissipation devices, the S.C. Sierra Club and S.C. Wildlife Federation sent a notice threatening to sue federal and state authorities if the devices weren’t removed. Learning about the concerns of local environmental groups and possible violations of the Endangered Species Act, S.C. Department of Health and Environmental Control has ordered that the walls must be removed by July 28th, 2016. Although this removal means that beach front home owners will be more vulnerable to shoreline change, Loggerheads and other sea turtles will have the opportunity to nest on the beach. And with over 90 nests on Harbor Island, SC (a 1400 acre barrier island) alone, Loggerheads are being given the chance to reemerge has a healthy and thriving population.

Read more on these devices and DHEC’s ruling here.

 

It's a long journey from the nest to the ocean.

It’s a long journey from the nest to the ocean.

2 Comments

  1. William Barnhill
    Jul 22, 2016

    So will these wave dissipation walls be going back up after the nesting season is over? I’m not sure how easily they can be installed and then taken back down, but I’m sure the beachfront property owners will think of it as a major pain. Interesting stuff.

    • Emily Hall
      Jul 22, 2016

      Thank you for the feedback! To my understanding, both the Citadel (who developed the device) and SC Department of Natural Resources are finishing up reports on the effectiveness of the device; due out in late summer and fall. I could see them trying to re-install the devices if they do indeed prove to be effective, but likely not during nesting season. It will be interesting to see how the state chooses to balance these two issues.

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