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Abstract Species across the planet are shifting or expanding their ranges because of climate change. These are climate migrants. Although climate migrants are well documented, their impacts on recipient ecosystems are not. Climate migrants that are also ecosystem engineers (species that modify or create habitats) will likely have profound effects on ecosystems. The Atlantic marsh fiddler crab,Minuca pugnax, is a burrowing crab that recently expanded its range into the northeastern United States. In its historical range,M. pugnaxenhances the aboveground growth of the cordgrassSpartina alterniflora, a plant critical to marsh persistence. In a control‐impact study, however, we found thatSpartinaaboveground biomass was 40% lower whenM. pugnaxwas present. Thus, the positive effect ofM. pugnaxonSpartinaaboveground biomass flipped to a negative one in its expanded range.Spartinabelowground biomass was also 30% lower on average when crabs were present, a finding consistent with what is seen in the historical range. These impacts onSpartinaare likely due to burrowing byM. pugnax.Benthic microalgae was, on average, 45% lower when crabs were present. Fiddler crabs eat benthic microalgae, and these results suggest that fiddler crabs can control algal biomass via grazing. Because fiddler crabs reduced the biomass of foundational primary producers in its expanded range, our results imply thatM. pugnaxcan influence other saltmarsh functions such as carbon storage and accretion as they expand north. Most strikingly, our results suggest that as species expand or shift their range with climate change, not only can they have profound impacts in their new ranges but those impacts can be the inverse of what is seen in their historical ranges.
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The fiddler crab Minuca pugnax (Smith, 1870) (Decapoda: Brachyura: Ocypodidae) reduces saltmarsh algae in its expanded range
Abstract It is well known that species across the world are expanding or shifting their ranges because of climate change. Yet, we know little about their impact on the habitats they colonize. In an observational study, we examined the effect of the fiddler crab Minuca pugnax (Smith, 1870) on benthic microalgal biomass in salt marshes in its expanded range (northeastern Massachusetts, USA). We found that plots with M. pugnax had, on average, 74% lower diatom biomass and 77% lower cyanobacteria biomass than plots without M. pugnax. Our results indicate that this climate migrant can impact saltmarsh functioning by limiting benthic microalgal biomass.
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- PAR ID:
- 10227686
- Date Published:
- Journal Name:
- Journal of Crustacean Biology
- Volume:
- 40
- Issue:
- 6
- ISSN:
- 0278-0372
- Page Range / eLocation ID:
- 668 to 672
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/jcbiol/ruaa073
