Habitat decoupling via saltmarsh creek geomorphology alters connection between spatially-coupled food webs
Article
Lesser, JS, Bechtold, CA, Deegan, LA et al. (2020). Habitat decoupling via saltmarsh creek geomorphology alters connection between spatially-coupled food webs
. ESTUARINE COASTAL AND SHELF SCIENCE, 241 10.1016/j.ecss.2020.106825
Lesser, JS, Bechtold, CA, Deegan, LA et al. (2020). Habitat decoupling via saltmarsh creek geomorphology alters connection between spatially-coupled food webs
. ESTUARINE COASTAL AND SHELF SCIENCE, 241 10.1016/j.ecss.2020.106825
Consumer-mediated movement can couple food webs in distinct habitats and facilitate energy flow between them. In New England saltmarshes, mummichog (Fundulus heteroclitus) use the flooding spring tides to access the high marsh platform and eat invertebrate prey, coupling the high marsh and aquatic creek food webs by gathering energy produced on the high marsh and making it available to the aquatic food web. Changes in the geomorphology of saltmarsh creek edges greatly influence the survival, biomass, and resource use of mummichog populations. Here, we use gut content analysis and field surveys to quantify the effect of altered creek edge geomorphology of mummichog predation on terrestrial invertebrate prey found on the high marsh surface. Fish populations in creeks with greater connectivity had a higher total biomass of terrestrial invertebrates in their guts. However, bomb calorimetry showed no difference in the average caloric content of mummichog individuals from creeks with different creek edge geomorphology. Additionally, we did not observe differences between the biomass and length distributions of mummichog in those creeks. While altered creek edge geomorphology has no effect the condition of the individual mummichog, it does decrease the total number of mummichog supported by a marsh creek and therefore decreases the total amount of high marsh production fluxed by mummichog to the aquatic habitat, decreasing coupling between the terrestrial and aquatic food webs.
