Anthropogenic Threats to Alligator Snapping Turtles (Chelydridae: Macrochelys)

Abstract

With the conservation status of Macrochelys (alligator snapping turtles) being examined at the national level, our objective was to compile categorical data on threats from anthropogenic interactions. We included information from (1) author-collected anecdotes on human-turtle interactions and (2) radiographs to assess the prevalence of ingested fishing hooks. We placed 173 interactions involving 192 incidents into 9 IUCN threat categories and found bycatch involving fish hooks to be 4 times more numerous than the second-most numerous threat, turtle persecution. Fishing bycatch resulted in a high proportion of turtle mortalities (39%), and bycatch incidents in several cases preceded the highest-mortality threat (53%), persecution of individuals involving shooting or blunt trauma. We recommend fishing bycatch-mitigation measures and educational efforts to help conserve Macrochelys.

Distribution Patterns and Factors Influencing Relative Abundance of the Alligator Snapping Turtle (Macrochelys temminckii) in Mississippi

“…Three individuals were found crawling through extremely shallow water in a roadside ditch, a small puddle near a levee, and a shallow urban spillway. Poaching and bycatch mortality on fishing equipment are 2 of the major current threats to M. temminckii populations range wide (Shook et al 2023 [this issue]). Three M. temminckii were caught on rod and reel, and a 45-kg male was subsequently killed and found to have survived a gunshot wound to the head from a prior encounter with humans.…”

Comparing cost, effort, and performance of environmental DNA sampling and trapping for detecting an elusive freshwater turtle

“…Conventional trapping of M. temminckii is labor intensive, difficult to scale, and frequently results in low capture probabilities (e.g., Johnson, 2020). Additionally, a federal listing decision for M. temminckii because of threats from harvest, anthropogenic persecution, and habitat loss or fragmentation (Shook et al., 2023; USFWS, 2021) could result in further permitting logistics and constraints on conventional trapping. Thus, M. temminckii is an excellent focal species for contrasting eDNA with conventional measuring and monitoring.…”