Up to October 2007, there were 46 turtle strandings on Cumberland that year: 36 loggerheads, 7 Kemp’s ridleys, and 3 green. Figure 1 shows totals for 2006 and 2007 through October 1.
Numbers of Stranded Sea Turtles on Cumberland Island, GA 2006-2007 |
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YEAR | CC | LK | CM |
2006 | 57 | 6 | 5 |
2007 (as of Oct. 1) | 36 | 7 | 3 |
CC – loggerhead LK – Kemp’s ridley CM – green |
Over time, the clearest trend to observe is that stranding numbers continue to increase. During the 1981 to 1985 period, the average number of dead sea turtles documented on the island was 49.6. Based on strandings from 2001-2006, that number is now 88, almost double. Figure 2 depicts the 25-year trend through 2005.
Figure 2 (Click image to enlarge)
Stranding Percentages on the Rise Among Green Turtles and Kemp’s Ridleys
The total of 68 sea turtle strandings in 2006 is less than the previous five year average of 92.2 dead turtles per year. Because there is great annual variability, a clearer picture emerges by looking at five-year averages. A close look at the stranding data from 1981 through 2005 shows that while stranding numbers continue to increase, the percentage of dead loggerheads has consistently dropped for each successive five-year period, from an initial 87.9% to 75% for the most recent period (see Figure 3), as the percentages of other species have increased.
The combination of green turtles and Kemp’s ridleys, which represented 11.3% of the island sea turtle strandings between 1981 and 1985, now make up 23.5% of the stranded turtles. The reasons for this are not clear, but it is likely that there has been an increase in the number of those species. Leatherback and hawksbill strandings are too few in number to assess trends.
Figure 3 (Click image to enlarge)
For information on Strandings in 2004, go here.