At PIE, mummichog (Fundulus heteroclitus) use the spring-cycle high tides to access the flooded 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 bomb calorimetry to assess individual mummichog caloric content per gram of biomass at 4 PIE creeks known to present different geomorphologic patterns in their low marsh zones. These data can be used for the assessment of the impact of low marsh geomorphology on mummichog caloric content and energy production in PIE food webs. These data were included as part of two studies “Habitat decoupling via saltmarsh creek geomorphology alters connection between spatially-coupled food webs” (Lesser et al. 2020) and “Cross-habitat access modifies the ‘trophic relay’ in New England saltmarsh ecosystems” (Lesser et al. 2021).