Climate change is enabling the redistribution of foundation species, which may affect ecologically and economically important ecosystem functions and organisms that are associated with these environments. One evident example of this distribution shift occurs in the Gulf of Mexico where black mangroves are expanding into saltmarshes. While the climate mechanism facilitating black mangrove expansion is understood, less is known about the consequences of replacing salt marsh habitat with black mangroves. Salt marshes provide habitat to many important species, including blue crabs and brown shrimp. We conducted field sampling and manipulative experiments to help illuminate some of the unknown effects from this shift in vegetation species. First, we determined if there was a change in community structure as ecosystems shift from salt marsh to black mangrove forest by collecting nekton and benthic samples from each habitat. Secondly, using tethering experiments, we measured predation intensity in salt marshes and black mangroves.
Results/Conclusions
Communities were significantly different after mangrove encroachment (p < 0.001). Nekton were significantly (p < 0.01) more abundant in sites without mangroves, and the communities shifted from shrimp to crab dominated. Predation was significantly higher (P < 0.01) in black mangrove dominated wetlands and may account for the observed community differences.