Conservation: Conservation Evaluation

Hatchlings rescued from nest 07-025a which had an air-dammed stope were released at dusk and scampered across South Beach to enter the Atlantic Ocean.

Final evaluation of our conservation effort is based upon hatching success (computed by GaDNR from our spreadsheets) and the number of hatchlings (computed by us) reaching the ocean. The number of hatchlings produced from year to year is highly variable and dependent upon contingency; the history of a given nest and a given season; both of which are highly variable.

Once hatched, baby sea turtles must exit from the nest, scamper across a beach populated by hungry raccoon, Ghost Crabs, and feral hogs. In the ocean, hatchlings enter a swimming frenzy for approximately 72 hours, apparently in a dispersal mode to thwart predation by shore birds, fish, and other potential predators. Estimates of the numbers of hatchlings necessary to produce a single adult sea turtle capable of reproduction at 20 to 30 years of age range from 1,000 to 10,000.

We prefer the lower estimate, one reproductive adult sea turtle for every 1,000 hatchlings making it into the ocean. If this estimate is accurate, one can compute the number of adult sea turtles produced by each season's work. From this total one can subtract the number of dead sea turtles found on an Island's beaches in a given year. Subtracting the estimated number being removed from the number being produced each year gives an idea of the overall success of the sea turtle conservation movement in our region.

Compute those numbers for yourself and predict the status of sea turtles in Georgia in the future.

For Example: In 1996 6,980 hatchlings entered the sea from our program; if 1 in 1,000 survived to reproductive age: 6,980/1000 = 6.98 loggerheads into population - 8 lost to stranding would suggest that we actually lost 1.02 loggerheads in 1996! Of course, it is not this simple, but it does give an order of magnitude to the conservation problem.

Year Nests Hatchlings Loggerhead
Strandings		 Net
Production
2009  
2008 143 11704 4  
2007 51 2882 1  
2006 124 9195 2  
2005 115 9140 5  
2004 59 3785 5  
2003 141 11683 10  
2002 77 3739 3  
2001 51 3278 7  
2000 112 9960 4  
1999 125 6900 15  
1998 86 4144 16  
1997 96 7369 5  
1996 118 6980 8  
1995 136 4277 9  
1994 184 8110 11 -2.9
1993 74 4898 0 +4.9
1992 148 7312 4 +3.3
1991 105 3271 5 -1.7
1990 145 9260 13 -3.7

The pattern of decline is readily apparent in these data. The decline of the sea turtles is a worldwide phenomenon as has been documented in The National Academy of Science publication, "Decline of the Sea Turtles."

It is this real-world problem that forms the basis for The St. Catherines Sea Turtle Conservation Program and our resultant Science Education Program.