Grant: Discovery Grants Program - Individual

My long-term goal is to understand which marine species will survive the Anthropocene. My premise is that species' extinction risk depends upon the interaction of population growth rates with fishing mortality. Put simply, a species will go extinct if the rate of fishing mortality is greater than the rate at which the population can replace itself - the population growth rate. This framing leads to two fundamental ecological questions. First, how does respiratory metabolism shape the pattern of life histories and population growth rates across the globe? Second, where are the places where fishing mortality is greater than species' population growth rates? Much of our understanding of global biodiversity comes from well-trodden terrestrial vertebrate exemplars. Sharks offer an independent aquatic test of many established theories, and my 2013 NSERC Discovery and Accelerator grants enabled me to branch into two new research themes: respiratory metabolism and global biodiversity patterns. My integrated research program now spans life histories from organismal metabolic processes to global patterns in population dynamics, and I am positioned to exploit two key opportunities. The first opportunity is that I now have the requisite components to test many macroecological and macroevolutionary hypotheses, using sharks as an exemplar, including: a dated phylogeny, compete distribution maps and IUCN extinction risk estimates for all species, plus a rapidly growing database of life history and ecological traits (SharkTraits). Second, I have successfully dissected the metabolic basis of the climate-change responses of species, and I am poised to apply these techniques to understand overfishing and extinction risk.  I will bridge three currently unconnected, but related, theories to develop a metabolic biogeography theory of population growth and extinction risk, namely: (1) Pauly's Gill-Oxygen Limitation Theory, (2) Southwood's Ecological Template, and (3) Clarke's economic Discounting Theory of extinction risk. The core of my proposal spans life histories -- from respiratory metabolism to global patterns -- and the intersection of population growth rates with overfishing, as driven by economic discounting.  My long-term goal will be realized through four short-term objectives, to understand how: (1) gills influence metabolic rates, (2) gills influence life histories and population growth rates, (3) gills (and environment) shape spatial patterns of population growth, and (4) population growth rate intersects with fishing mortality causing extinction risk. My work has significant benefits for Canada, producing at least 60 publications, plus 17 highly employable HQP with theoretical and empirical experience bridging from respiratory physiology to global sustainability - from a lab with a world-class record of providing and communicating salient science that shapes societal decisions.