Conservation: Conservation Evaluation

St. Catherines Island Survival Center veterinarian, Dr. Terry Norton, performs a necropsy on a dead Loggerhead in 2006 to determine cause of death.

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.

Year Nests Hatchlings Strandings Net Production
2006 124 9195 x  
2005 115 9140    
2004 59 3785    
2003 141 11683    
2002 77 3739    
2001 51 3278    
2000 112 9960    
1999 125 6900    
1998 86 4144    
1997 96 7369    
1996 118 6980    
1995 136 4277 9  
1994 184 8110 11  
1993 74 4898 0  
1992 148 7312 4  
1991 105 3271 6  
1990 145 9260 13  

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.