We examine the impacts of moderate nutrient enrichment on the production mummichog, Fundulus heteroclitus, as part of a 10-year whole ecosystem experiment in a Plum Island Sound saltmarsh. In the initial stages of nutrient enrichment we observed a classic bottom up stimulation response in fish production. However, after the first six years fish production declined rapidly. The mechanism for the decline is not known but we hypothesize indirect interactions with other saltmarsh consumers may play an important role, as well a habitat alteration. Our results demonstrate that long-term nutrient enrichment can have complex impacts on the production of saltmarsh fish that are not predictable by classic bottom up/ top down control theory. Our findings suggest that eutrophication and climate change induced sea level rise will have synergistic negative effects on the production of saltmarsh fish primarily through habitat alteration and loss. In 2016, we conducted a 15N tracer experiment to test the concept of bottom up vs creek edge and marsh platform control of mummichog production and have been processing and analyzing samples.
- Howard, E. M., Forbrich, I, Giblin, A E., Lott, D E III, Cahill, K L, Stanley, R H R. (2018). Using noble gases to compare parameterizations of air-water gas exchange and to constrain oxygen losses by ebullition in a shallow aquatic environment. Journal of Geophysical Research: Biogeosciences, 123, 2711–2726. https://doi.org/10.1029/2018JG004441
- Langley, J A, Chapman S K, La Pierre K J, Avolio M, Bowman W D, Johnson D S, Isbell F, Wilcox K R, Foster B L, Hovenden M J, Knapp A K, Koerner S E, Lortie C J, Megonigal J P, Newton P C D, Reich P B, Smith M D, Suttle K B, Tilman D. 2018 Ambient changes exceed treatment effects on plant species abundance in global change experiments. Glob Change Biol. 24: 5668– 5679. https://doi.org/10.1111/gcb.14442
- Nelson, J.A., Johnson D S, Deegan L A, Spivak A C, and Sommer N R. 2018. Feedbacks Between Nutrient Enrichment and Geomorphology Alter Bottom-Up Control on Food Webs. Ecosystems. https://doi.org/10.1007/s10021-018-0265-x
- Wigand, C., Watson E B Watson, Martin R, Johnson D S, Warren R S, Hanson A, Davey E, Johnson R, Deegan L A. 2018. Discontinuities in soil strength coupled with sea level rise contribute to destabilization of nutrient-enriched creeks. Ecosphere. Vol 9. https://doi.org/10.1002/ecs2.2329
- Crosby, S. C., Angermeyer A, Adler J M, Bertness M D, Deegan L A, Sibinga N, and Leslie H M. 2017. Spartina alterniflora biomass allocation and temperature: implications for salt marsh persistence with sea level rise. Estuaries and Coasts (2017) 40: 213. https://doi.org/10.1007/s12237-016-0142-9
- Kearney G, W. S., G. Mariotti G, Deegan L A and Fagherazzi, S. 2017. Stage-discharge relationship in tidal channels. Limnol. Oceanogr. Methods. doi:10.1002/lom3.10168
- Johnson, D S, Warren, R S, Deegan, L A and Mozdzer, T J. (2016), Saltmarsh plant responses to eutrophication. Ecol Appl, 26: 2649–2661. doi:10.1002/eap.1402
- Crosby, S C, Sax D, Palmer M , H. S. Booth, L. A. Deegan, Bertness M D, Leslie H M. 2016. Salt marsh persistence is threatened by predicted sea-level rise. Estuarine, Coastal and Shelf Science 181: 93-99
- Kearns G, P., J. H. Angell G, E. Howard G, L. A. Deegan, R. H. Stanley, and J. L. Bowen. 2016. Nutrient enrichment induces dormancy and decreases diversity of active bacteria. Nature Communications.
- Davis JL, Currin CA, O’Brien C, Raffenburg C, Davis A (2015) Living Shorelines: Coastal Resilience with a Blue Carbon Benefit. PLoS ONE 10(11): e0142595.
- Johnson, D.S. 2014. Weeds making waves. Essay. Science 344:255
- Johnson, D.S. and M. I. Short. 2013. Chronic nutrient enrichment increases the density and biomass of the eastern mudsnail, Nassarius obsoletus. Estuaries and Coasts 36: 28-35
- Pascal, P-Y, J.W. Fleeger, H.T.S. Boshker, H. Mitwally, and D.S. Johnson. 2013. Chronic nutrient-enrichment influence on mudflat food web in a New England (USA) estuary. Marine Ecology Progress Series. 474:27-41
- Deegan, L.A. D.S. Johnson, R.S. Warren, B.J. Peterson, J.W. Fleeger, S. Fagherazzi, and W. Wollheim. 2012. Coastal eutrophication as a driver of salt marsh loss. Nature 490:388-392.
- Chronic Nutrient Press Differentially Alters Salt Marsh Ecosystem Functions. L. Deegan. Joint Aquatic Science Meeting, Portland, Oregon. May 19-26, 2014.
- MBL Undergraduate Research Symposium. The effect of diet on fatty acid content and assimilation efficiencies in Fundulus heteroclitus. Alison Hall (Carelton College Biology Department and Woods Hole Marine Biological Laboratory Ecosystems Center), James Nelson (Woods Hole Marine Biological Laboratory Ecosystems Center) and Amanda Spivak (Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institute) Aug 20, 2014.
- Undergraduate Honors Thesis: Bethany Williams, Florida State University: Sea-level rise effects on the coffee-bean snail, Melampus bidentatus
- Nelson, James A., Johnson David S., Deegan Linda A., Spivak Amanda C., Moore Nathalie R. Geomorphology modifies bottom-up control on food webs. Ecological Applications.
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