Abstract Climate-driven range expansions are reshaping coastal ecosystems, and many marine ectotherms are shifting poleward in response to warming ocean temperatures. In the northwest Atlantic, Minuca pugnax (Smith, 1870), the Atlantic marsh fiddler crab, has extended its range northward into the rapidly warming Gulf of Maine (GoM). We present the first monitoring study to track M. pugnax in salt marshes in New Hampshire, USA. We evaluated the effectiveness of using a non-destructive “burrowscope” (a commercial borescope) for estimating M. pugnax densities in real time during field surveys. Burrowscope-based occupancy measurements were incorporated into standard monitoring surveys and compared to the widely used surveying method of burrow counting. Surveys conducted at two salt marshes in Great Bay, New Hampshire revealed small but established populations of M. pugnax, with higher densities observed at the Bunker Creek site than at Sandy Point. The integrated burrowscope-based approach revealed the traditional method of burrow-counting overestimated M. pugnax density. On average, there were 2.4 burrows per individual M. pugnax. This overestimation likely resulted from counting unoccupied or abandoned burrows, some of which were opportunistically used as a refuge by other species (e.g., by the mud crab, Rhithropanopeus harrisii (Gould, 1841)). The integrated burrowscope method was highly accurate for real-time identification of burrow occupants (91.7%) and moderately accurate for determining M. pugnax sex (75%). By providing real-time burrow occupancy data, the burrowscope enhanced the accuracy of standard monitoring protocols used to estimate M. pugnax densities. The method is non-destructive, easy to use, and inexpensive, making it a valuable tool for field studies of burrowing animals. As M. pugnax continues to expand its range, refined monitoring approaches, such as that used herein, will be essential for assessing the species ecological impacts on GoM salt marsh ecosystems.
LaPlante et al. (Sat,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: