Turtle Talk
  • Home
  • Loggerhead Sea Turtle
  • What you can do
  • Symbolic Adoption Program
  • YouTube
  • DNA Study

Follow along to read the up to date sea turtle nesting info!

Final Turtle Count for 2022 Season - Nests: 351 False Crawls: 236
2023 - stay tuned.

Understanding Loggerhead Population Demographics: the “Why” behind Genetic Studies

7/12/2021

0 Comments

 
Blog Post By: Ashlyn, Sea Turtle Intern

Setting the scene: On every beach spanning the Atlantic Coast from North Carolina to Florida, night patrollers would be walking the beach from dusk until dawn, attempting to encounter every nesting loggerhead that emerges from the ocean to nest along the dunes. Tags must be given to each turtle encountered with thorough documentation occurring throughout the night, and fingers must be crossed that no turtles evade the nightly patrol. A logistical catastrophe.
 
Tagging studies on nesting beaches, the historical common practice to estimate nesting frequencies among other population demographic parameters, cannot obtain the magnitude of samples required for confident determination of sea turtle population demographics. Therefore, Dr. Brain Shamblin and his team at University of Georgia, altered the precedent. Since 2010, the Edisto Beach State Park beach along with beaches all along the Southeastern Coastline have participated in Dr. Shamblin’s genetic study of loggerhead sea turtles, allowing for a deeper understanding of loggerhead nesting population demographics, furthering sea turtle conservation efforts.
 
Rather than a focus on directly on the mother turtle, focus shifts to the eggs to obtain information about the mother. From each nest discovered on the beach, a single egg is obtained from the clutch within 15 hours of oviposition. In its entirety, the egg contains both the mother’s and father’s genetic material; however, the shell of the egg contains genetic information solely from the mother. For this reason, the yolk contents of the egg are sacrificed, and the shell of the egg is preserved in a 70% ethanol solution to allow for the isolation of DNA from the eggshell of the mother loggerhead sea turtle. Genotypes are derived from a single-locus from the unincubated egg shell, with an accuracy rate of 97.6% to the genotype that would have been derived if taken directly from a skin sample of the mother loggerhead.
 
The development of this single locus genotype frequenting technique serves as a groundbreaking noninvasive method in furthering our understanding of sea turtle population demographics. This methodology additionally is applicable to other marine turtle populations in which direct interception of the nesting female is logistically not feasible when genetics studies are being conducted.
 
For more information regarding the nesting patterns of loggerheads on the EBSP beach, visit www.seaturtle.org for maps and data information. For more information regarding the genetic extraction process within the laboratory, visit the website of Dr. Brain Shamblin for links to his published works.

0 Comments



Leave a Reply.

    Leah Schwartzentruber

    Sea Turtle Specialist 
    Edisto Beach State Park
    8377 State Cabin Road
    Edisto Island, SC, 29438

    Archives

    January 2023
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    October 2021
    August 2021
    July 2021
    June 2021
    May 2021
    January 2021
    October 2020
    August 2020
    July 2020
    June 2020
    May 2020
    October 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016

    RSS Feed

Proudly powered by Weebly
  • Home
  • Loggerhead Sea Turtle
  • What you can do
  • Symbolic Adoption Program
  • YouTube
  • DNA Study