SI 2021 Turtle DNA Results Are In

As the Seabrook Island Turtle Patrol gets ready to begin its season, it is a good time to look back at the results for 2021 based on DNA findings.

One egg from each nest is sacrificed so that a piece of the shell can be used by DNR (in conjunction with the University of Georgia) to identify the DNA of the mother of each nest. This DNA mapping allows researchers to follow how many nests are being laid and where, how many females are laying eggs, and how often the turtles nest. The information is vital to determine the status, and ultimately help in the conservation, of this endangered species.


Seabrook Island is not the only place to participate in this study, so it is interesting to compare our data with each location. We have participated in the program since 2010 and here are some findings from the Seabrook Island 2021 data:

  • From 2010 through 2021, 359 unique mama turtles have been identified to have laid a nest on Seabrook Island
  • DNA has been assigned to 68 of the 76 nests laid in 2021
  • The 68 ID’d nests were laid by 41 different mothers
  • Only 8 of the 41 mothers were first-year in the system
  • We say the mothers lay every 2 to 3 years and in the years they lay, they lay an average of 4 or 5 nests. 
    • In 2021, the average number of nests laid by mothers who have ever laid on Seabrook was 4 nests
    • The average number of nests laid by “new” mothers was 3.77
    • Six different mothers laid 6 nests (Not all of those nests were on SB)

Stories of specific Mamas:

  • Mama CC006804: This rock-climbing mama laid her nest under a bush in the back yard of the first house north of the club. She has laid 15 nests since 2013 but the first on Seabrook. She laid 6 nests in 2021 with the other 5 on Botany. 
  • Mama CC014395: This is the mama who laid the last nest of South Carolina on Seabrook Island on August 27. She was a first-year mama but laid 3 other known nests in 2021 before coming to Seabrook.  Her other nests were on Little Cumberland, then Fripp Island, then Litchfield.
  • Mama CC0014365: First-time mama in 2021. She laid nests 66 and 73 on Seabrook. Nest 73 was a late find when it was found by raccoons before we located it. Her other two nests were on Otter Island and then Blackbeard Island (near the Florida border) where it was also a Wild Nest.
  • Mama CC006108: Laid 6 nests on Seabrook in 2021 (3, 21, 36, 50, 67 and 70). To date, she has laid 28 nests, 27 of which were on SBI. The one not on SBI was near the spit on Kiawah. She has nested every other year since 2011. 
  • Mama CC003840: Has laid 18 nests since 2008 (Kiawah started reporting earlier). Two of these were laid on Seabrook, including 2021 Nest 5. The rest were all laid on Kiawah.
  • Mama CC004197: Four of her 5 nests laid in 2021 were laid on SBI (14 and 30 on Zone 4 then 43 and 59 on Zone 2). She has laid 27 nests since 2011 (2011, 2013, 2014, 2016, 2018, 2019 and 2021).  Obviously, she didn’t read the book that she was supposed to take a year off between nest laying years.  Six of her 27 nests were on SBI, the rest on Kiawah.

To learn more about Seabrook Island Turtle Patrol, click here.

-Submitted by Judy Morr

(Image credits: Tidelines media library)

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