By Mary Pringle for The Island Eye News
On the morning of Aug. 18, Turtle Team members were happy to see many tracks where hatchlings had climbed out of the green sea turtle nest that was laid on June 24 near Ocean Club Villas in Wild Dunes and moved further south.
This was our second green turtle nest; our first was in June 1998. It incubated for 55 days, which was about 10 days faster than expected.
Hatchling greens crawl with both their front flippers moving forward at the same time, whereas loggerheads crawl with an alternating gait using their front flippers. We were surprised at the different appearance in their tracks, with the greens appearing to be much wider. These turtles are a little larger than loggerheads as hatchlings and as adults. Greens are also a darker color at this age, with a white stripe on the trailing edges of their flippers. Loggerhead hatchlings can vary in color from dark grayish brown to tan even among individuals in the same nest.
As of the third week of August, more than half of the turtle nests on the Isle of Palms and Sullivan’s Island had already produced hatchlings. Incubation is averaging 56 days, and hatch success is close to 80%. It is normal for the early nests that were laid before it got consistently hot at the beginning of July to take longer.
The more heat the eggs get, the faster they develop. There is a delicate balance between incubation that is too fast or too slow. We are told by the experts at the South Carolina Department of Natural Resources that about 56 days is ideal. As the final nests hatch, we are likely to see more 48- to 50-day nests. Too much heat and too short incubation times can produce hatchlings that aren’t as strong and healthy. We have had a few nests where a large number of eggs failed to develop and hatch, and we have heard from other nesting projects that they are experiencing the same problem, but no one really knows why. We hope we can maintain a good hatch success average.
The rules from SCDNR require us to do a “nest inventory” no less than 72 hours after the first hatchlings come out of each nest. We have to keep a close watch on all nests, checking them every morning, so we know exactly when this happens.
At that time, we excavate the contents of the nest, count the undeveloped eggs and any dead hatchlings and release any live hatchlings that are healthy and mature enough to swim away in the ocean. The inventory of the green turtle nest showed us that only four eggs out of 101 failed to develop, with no live hatchlings left in the nest three days after the turtles came out.
Since one egg in the nest was found broken in June, hatch success was 95%.
Because of the coronavirus, the public cannot attend these events in 2020, much to the disappointment of our volunteers as well as residents and visitors to our islands who look forward to seeing hatchlings released to swim out into the ocean. Only two authorized people are allowed to conduct each inventory and collect the information which is submitted online to a national database.
Our final nest will not be finished until sometime in October, so we are hoping that tropical storms and hurricanes will allow them to survive.