Seabrook Island 2016 Turtle DNA Results Are In

As the Seabrook Island Turtle Patrol gets ready to begin their season on May 7, it was a good time to look back at the results for 2016 based upon DNA findings. One egg from each nest is sacrificed so the membrane 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 much information to become known about the Loggerhead Sea Turtles.

Seabrook Island has participated in the program since 2010. Here are some findings from the 2016 data.
– 59 of the 60 nests laid on Seabrook Island in 2016 have been mapped
– Those 59 nests were laid by 46 unique mothers
– 19 of those 46 mothers had never before been identified in the system, regardless of beach
– Those 46 mothers laid a total of 156 nests in 2016 on 26 different beaches.
– Of the 156 nests, 59 (37.8%) were on Seabrook Island with an additional 41 nests on Kiawah, 8 on Botany Bay Plantation, 7 on Folly, and 4 on Botany Bay.

Some of the mothers have become our “friends”
– Mother CC000530 has laid 17 nests on Seabrook Island since first identified in 2010. Typically the mother turtles lay only every other year or every three years. CC000530 laid on Seabrook Island in both 2010 and 2011 and in 2015 and 2016. In both 2015 and 2016, she laid Nest #1. She also laid on Seabrook in 2013. Her only other nests are one nest on Kiawah in each 2011 and 2013. She averages a clutch size of 140 eggs with a 70% hatch rate. A successful mother indeed.
– Mother CC000570 has laid 19 nests since 2010 with the last 14 being on Seabrook Island. She laid 6 of the 60 nests of 2016. She averages 141 eggs per clutch and an 83% hatch rate. In 2016, 2 of her nests were on Pelican Beach (Zone 1) and 4 were on North Beach (Zone 3). She was the mother who came in at dusk on July 21 near Boardwalk 1 where Nest 5 was boiling at the same time. It would have been REAL interesting if Nest 5 was also hers but it was not. Hers was Nest 6 which was on Zone 1 and it boiled on July 16.
– Mother CC009950 was a new mother to the system in 2016. She laid 2 nests on Seabrook Island. The first was laid on May 26 in front of the Beach Club Villas. On July 7 she laid her next nest by going through “tent city”. She didn’t lay any other nests in 2016.
– Mother CC002043 laid 3 nests on Seabrook Island in 2016 after 2 here in 2013. She also laid one on Pritchards Island in years 2011 and 2016. She also visited Fripp Island twice in 2016 and Kiawah twice in 2013 and Hunting Island State Park 3 times in 2011.
– Mother CC002055 laid 7 nests on Kiawah in 2011 and 2013 before moving to Seabrook Island for 2016. Both of her nests were laid on North Beach near the “No Dogs Allowed” sign.
– Mother CC002058 has laid 4 nests on Kiawah and 12 nests on Seabrook Island since 2010. In 2016, she laid 3 nest on each. Her Seabrook Island nests were one on Zone 2 (between Boardwalk 6 and 7) and two on Zone 4 (North Beach).

Some other fun facts:
– Mother CC006469 laid nests on 5 different beaches in 2016. One each this sequence: Seabrook Island, Kiawah, Hunting Island State Park, Botany Bay Plantation and Folly Beach. In 2013, she laid on Folly and Kiawah.
– Mother CC008942 laid Seabrook Island Nest 11 on May 31 before heading all the way to Cape Hatteras to lay 2 nests in July.
– Mother CC009122 laid a nest on Amelia Island, Florida on June 11 then laid a nest on Kiawah just 13 days later. It was another 31 days until she laid her nest on Seabrook Island just past the last building for Camp St. Christopher.
– Of the 223 mothers who have laid on Seabrook Island since 2010, 78 of those laid somewhere in 2016. 36 of those 78 were only somewhere other than Seabrook Island.
– Theoretically, mothers who laid 2014 or prior would have nested again by 2016. 55 of the 189 mothers who laid on Seabrook Island in 2014 or prior have only laid in that year.

As more years pass and more DNA data is gathered, science is providing us with a better picture of the nesting population of loggerhead turtles and their nesting patterns.

-Submitted by Judy Morr

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