The Status of Macrochelys temminckii (Alligator Snapping Turtle) in the Flint River, GA, 22 Years after the Close of Commercial Harvest

Macrochelys temminckii (Alligator Snapping Turtle) was petitioned for federal listing as threatened under the Endangered Species Act in 2012 as a result of population declines attributable in part to harvest for human consumption. The species was listed as threatened in 1992 in Georgia, where all harvest of the species was closed. Because little is known about how Alligator Snapping Turtle populations respond to protection, we surveyed Georgia's Flint River, which had originally been surveyed in 1989, to assess whether abundance of Alligator Snapping Turtles increased following close of commercial harvest. Our survey, conducted in 2014 and 2015 yielded captures of 52 Alligator Snapping Turtles with an overall catch per unit effort (CPUE) of 0.09 turtles/trap-night, as compared to 62 captures and a CPUE of 0.08 turtles/trap-night in the 1989 survey. Although CPUE was similar between the two studies, we observed differences among the lower, middle, and upper reaches of the river; CPUE increased in the lower reach, decreased slightly in the middle reach, and remained the same in the upper reach of the Flint River. Mean size (carapace length) of Alligator Snapping Turtles did not differ between the 2 surveys, but in 2014–2015 we caught nearly twice as many immature (<40 cm carapace length) turtles as adult males and females, and the highest proportion of immature turtles was captured in the upper reach. Our findings suggest that the Alligator Snapping Turtle population in the Flint River has not increased despite 22 years of protection from commercial harvest. Recovery may be hampered by life-history characteristics of the species including delayed maturity and low reproductive output; however, we cannot rule out possible ongoing mortality of Alligator Snapping Turtles from illegal harvest or drowning on abandoned limb lines, as has been observed in other populations.