Project: Collaborative Research: Mechanisms supporting persistence of a key plankton species during climate change on the Northwest Atlantic continental shelf

Description from NSF award abstract:
In the Gulf of Maine region, rapid warming of the ocean surface in recent years has raised concern in the research and resource management communities, fishing industry and the general public about effects on the coastal marine ecosystem. This interdisciplinary, collaborative project will improve understanding of the physical and biological processes controlling the abundance of a planktonic animal that is particularly important in the food web of the northeast coastal ocean. About the size of a grain of rice, the marine copepod Calanus finmarchicus is the primary prey for herring and other forage fish, as well as for the endangered northern right whale. This study will examine whether transport of C. finmarchicus into the Gulf of Maine from cold Canadian waters, in combination with growth and reproduction in the relatively cold Maine Coastal Current, is sufficient to supply the region with the numbers needed to attract and nourish the fish, seabirds and mammals that rely on its energy rich life stages, despite recent ocean warming. The research team will develop a computer model that links extensive understanding of the species' life history with ocean currents and temperature. Results from the model will be tested against field collections at two locations. This study will also contribute to the new Integrated Sentinel Monitoring Network, a joint effort planned by federal and state agencies with academic research participation to monitor future ecosystem change on the northeastern coastal shelf. It will train a graduate student and postdoctoral scientist in interdisciplinary research and also provide support for an early-career investigator.

The project will take a process modeling approach that takes into account regional and mesoscale interaction between life history and bathymetry and circulation to improve understanding of planktonic species distribution shifts. It will combine two decades of research on Calanus finmarchicus life history, including diapause, with a high resolution regional circulation model into an innovative application of a three dimensional, physical-biological model. The modeling approach represents an advancement of climate forecasts of species ranges by coupling a Lagrangian perspective with local processes to better resolve complex range boundaries. It will use Lagrangian parameters such as finite-scale or finite-time Lyapunov exponents, translating particle trajectories into scalar fields that represent the structure of the advective regime. The model will be informed by and tested with measurements of vital rates and demographic data collected on a research vessel at two time series stations. It will be used in backward-in-time and forward-in-time modes to test hypotheses about sources and destinations of C. finmarchicus in the Gulf of Maine, effects of match/mismatch in phenologies, and exploration effects of climate forced scenarios on advective pathways.