Distribution and Abundance of Diamondback Terrapins (Malaclemys terrapin) in Southwestern Louisiana

Abstract

Abstract The diamondback terrapin (Malaclemys terrapin) is a brackish-water turtle ranging from Texas to Massachusetts, as well as an isolated population on the island of Bermuda. Louisiana likely holds the most available habitat of any other state for the species (over 650,000 ha of brackish and salt marshes), yet little is known about terrapin distribution and abundance throughout coastal Louisiana. Knowledge is particularly scant in southwestern Louisiana, where only 12 specimen records exist, the most recent record being from 1972. We wanted to determine whether 1) terrapin populations persist in historical collection localities, 2) terrapin populations are present in additional coastal marsh localities, and 3) terrapin abundance differs among sites in southwestern Louisiana. We sampled for diamondback terrapins during 2011–2013 at 16 sites across southwestern Louisiana; all sites were near historical localities or other apparently suitable brackish or salt marsh habitats. We used unbaited fyke nets w...