Environmental forcing of primary production in the changing Arctic and sub-arctic seas

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The ongoing metamorphosis of northern seas hands us a natural experiment that must be tapped to unravel the effects of multiple environmental stressors on marine primary production (PP) and biogeochemical fluxes. For the Arctic in particular, the response of PP to natural and anthropogenic forcing (ice cover, light, nutrients & temperature) and the ensuing feedbacks on climate (e.g. release or capture of greenhouse gases) are subject to large uncertainties and debate. Research objectives for the next 5 years are to (1) elucidate the physical drivers of PP, (2) quantify biological steps of the nitrogen cycle that strongly affect PP, and (3) investigate Arctic/sub-Arctic connectivity with respect to nutrient loading and freshwater deliveries. Hypotheses will be tested with a combination of autonomous observation (moorings), culture work, historical data and ship-based process studies. The latter will rely on state-of-the-art techniques that use stable isotopes as tracers of carbon and nitrogen fluxes in situ (natural abundance) and during experimental incubations with 15N/13C-labeled substrates. As global fisheries continue to decline and northern waterways become safer, the value of new arctic resources is likely to soar. My research will assess the carrying capacity of northern seas in terms of the quantity and quality of the PP available to renewable resources. Quantitative understanding of fundamental, first-order ecological processes and their response to multiple environmental stressors will increase and improve the numerical models that constrain future scenarios. The new knowledge should empower Canadian managers, policy makers and industry with better means to evaluate, anticipate and adapt to the changing icescape and its impacts on ecosystem health and services. Other benefits to Canadians include a better grasp of marine ecosystems and crucial linkages between the far north and the coastal waters of Atlantic Provinces, as well as training of the next generation of biological oceanographers.