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.  

See:
Johnson, D.S., K.S. Martínez-Soto, S. Wittyngham, M. Pant, and E. Goetz. 2020. The fiddler crab Minuca pugnax (Smith, 1870) (Decapoda: Brachyura: Ocypodidae) reduces saltmarsh algae in its expanded range. Journal of Crustacean Biology 40: 668-672