I am actively engaged in basic and applied research to examine how consumer-resource relationships build the food web architecture that supports ecosystem function and resilience. I am currently involved in a number of concurrent projects that span a wide range of species, ecosystems, and questions. However, the unifying theme for all of these projects is visualizing and quantifying food web architecture to provide a mechanistic understanding of the structure and functioning of marine food webs food webs. This research is directly relevant to the recent decadal review of ocean science by The National Academy of Sciences, which highlighted changes in food web structure over the next 50 to 100 years as one of eight priority questions in ocean science. The ultimate goals of my research are to not only understand the processes and patterns of ocean food web architecture, but also provide the scientific support necessary to promote healthy sustainable human-environment interactions.
Current Research Projects:
A school of snapper patrol the reef crest in the Phoenix Islands. (Photo Mark Priest)
Coral reef food web architecture:
This project aims to identify links between food web architecture and reef resilience, and ultimately provide the scientific basis for coral reef conservation and sustainable human-environment interactions.
Gentoo penguins rearing young in Antarctica. (Photo: Michael Polito)
Ancient and modern Antarctic krill predator food webs
This research will help place recent ecological changes in the Southern Ocean into a larger historical context by examining proposed decadal and millennial-scale variation in predator trophic dynamics, population expansion and contraction, and large-scale shifts in the Antarctic marine food web.
Hawai'ian gold coral colony sampled
iat 450m depth near Makapuu, Hawai'i. Photo credit: NOAA Hawaiian Undersea Research Laboratory, DSRV
Pisces Pilots & Engineers, 2004.
Deep-sea corals as paleoarchives of past ocean ecosystem structure and function:
This project reconstructs past changes in open ocean ecosystem food web structure and biogeochemical cycling using deep-sea proteinaceous corals as biogenic archives.
Dr. McMahon tagging a juvenile whale shark off the coast of Saudi Arabia, Red Sea as part of the Red Sea Research Center whale shark tagging program (Photo Michael Berumen)
Tagging of large pelagic fishes:
This project couple satellite and acoustic tagging approaches to better understand the patterns and drivers of the amazing migration patterns of some of the ocean’s largest and most threatened species.
Mangroves act as valuable nurseries for many coral reef fishes. Protected among the roots and surrounded by nutrient rich water, juvenile coral reef fishes can mature with ample food and protection until they migrate out to join the adult population on offshore reefs. (Illustration E. Paul OBerlander WHOI)
Ontogenetic migration of fishes and coastal wetland nurseries
This project uses compound-specific stable isotope analysis in fish otoliths to identify essential coastal nurseries and migration corridors of fishes at the seascape level.
This project is part of an ongoing collaboration to construct ocean isoscapes at a range of spatial and temporal scales to examine ocean food web structure, biogeochemical cycling, and animal migration.
Compound-specific stable isotope analysis of individual amino acids.
Development of compound-specific stable isotope analysis approach to ecogeochemistry:
To realize the full potential of the CSIA approach for ecogeochemistry, I have a number of projects going to investigate the underlying biochemical and physiological mechanisms generating variability in individual compound fractionation through controlled laboratory experiments.