Panhandle Status and Distribution of the Alligator Snapping Turtle
In 2018‒19, FWRI researchers trapped 88 alligator snapping turtles (Macrochelys) in 547 trap nights (TN) for an overall catch per unit effort (CPUE) of 0.16 in the Florida panhandle. Excluding Dog Island and the Aucilla and Wacissa rivers, which likely lack Macrochelys populations, and the Choctawhatchee drainage, which apparently has depauperate populations, the CPUE was 0.23. Researchers trapped three 5-km sections of four large alluvial streams—Ochlockonee, Apalachicola, Choctawhatchee, and Escambia rivers—using 12 hoop-net traps and also trapped 130‒1,347-m sections of 32 smaller streams using six hoop-net traps. Researchers often had higher trapping success in small streams, and Macrochelys was often the only turtle species caught. The surveys failed to detect Macrochelys in three streams where they are known to occur, but researchers recorded the species for the first time in Cypress, Bear, Dry, and Wetappo creeks. Macrochelys was detected in 23 streams, and it likely occurs in most streams between the Ochlockonee and Perdido rivers with deep enough water and appropriate cover.
Although the Choctawhatchee River appears to provide good habitat for Macrochelys, this study had low trapping success (CPUE = 0.02) in 96 TN and failed to trap the species in 44 TN in 3 tributaries: Holmes Creek, Pine Log Creek, and Wrights Creek. The Choctawhatchee drainage is mostly undeveloped and has better water quality than many rivers where Macrochelys is abundant, such as the Escambia River.
Overall, researchers captured 45 males, 31 females, and 11 juveniles of undetermined sex. Genetic samples were collected from 72 turtles in 21 streams and from a hatchling found on Dog Island, Franklin Co. Most Florida rivers were never commercially trapped for Macrochelys, but incidental mortality from trotlines and bush hooks may be a problem in some rivers.