- Ph.D., University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS), 1996
- Primary productivity of tropical marine ecosystems
- Climate change (elevated temperature, salinity and pCO2) effects on tropical marine autotrophs
- Stress responses and adaptation to stress in tropical marine autotrophs (macroalgae, seagrass, mangrove)
- Biogeochemistry and nutrient cycling in tropical carbonate ecosystems
Our research is on nutrient cycling and primary production in tropical marine ecosystems and stressors that influence tropical seagrass, mangrove and algal communities. We are currently focused on climate change effects, including elevated temperature, salinity and pCO2, termed “ocean acidification”, on marine plant and macroalgal communities. We hypothesize that ocean acidification and elevated temperature affect photosynthesis, growth and calcification in tropical reef macroalgae with far-reaching ecological consequences. However, diverse pathways of inorganic carbon acquisition for photosynthesis and mechanisms of calcification may provide resistance to elevated ocean pCO2 in calcifying macroalgae. In addition, we are elucidating mechanisms causing seagrass mortality in Florida Bay, relevant to lagoons and estuaries world-wide.
Our research approach is to examine stress responses from the physiological to ecological scale, consider species life history, and focus on ecosystem-level indicators of stress, such as hypoxia and eutrophication. We are also interested in biogeochemical changes that destabilize foundation plant communities and thereby influence the sustainability of marine ecosystems. The majority of our work is in shallow tropical carbonate environments (lagoons and reefs) of South Florida, The Bahamas and wider Caribbean. We typically take an experimental approach to examine alternative hypotheses in mesocosms and field settings.
- Johnson, C.R., Koch, M.S., Pedersen, O., Madden, C. (2018) Hypersalinity as a trigger of seagrass (Thalassia testudinum) die-off events in Florida Bay: Evidence based on shoot meristem O2 and H2S dynamics. Journal of Experimental Marine Biology and Ecology 504, 47-52.
- Zweng, R.C., Koch, M.S., Bowes, G. (2018) The role of irradiance and C-use strategies in tropical macroalgae photosynthetic response to ocean acidification. Scientific Reports 8(1), 9479 https://doi.org/10.1038/s41598-018-27333-0
- Morey, S., Koch, M., Liu, Y., Lee, S.K. (2017) Florida’s oceans and marine habitats in a changing climate. In: Florida’s Climate: Changes, Variation, and Impacts. FSU http://purl.flvc.org/fsu/fd/FSU_libsubv1_scholarship_submission_1515510689_7e3d1fb9
Koch, M., Bowes, G., Ross, C., Zhang, Xing-Hai. (2013 electronic; 2014 print) Climate change and ocean acidification effects on seagrasses and marine macroalgae. Review paper: Global Change Biology 19, 103–132, DOI: 10.1111/j.1365-2486.2012.02791.x