Coupling of an individual-based population dynamic model of Calanus finmarchicus to a circulation model for the Georges Bank region

An individual-based life history and population dynamic model for the winte r-spring dominant copepod of the subarctic North Atlantic, Calanus Finmarch icus, is coupled with a regional model of advection for the Gulf of Maine a nd Georges Bank. Large numbers of vectors, each representing individual cop epods with elements for age, stage, ovarian status and other population dyn amic variables, are carried in a computation through hourly time steps. Eac h vector is updated at each time step according to development rate and rep roductive functions derived from experimental data. Newly spawned eggs are each assigned new vectors as needed. All vectors are subject to random mort ality. Thus, Loch life history progression and population dynamics of C. fi nmarchius are represented for the temperatures in the Gulf of Maine-Georges Bank region in the active season. All vectors include elements representin g depth, latitude and longitude. This allows coupling of the population dyn amics to the tide- and wind-driven Dartmouth model of New England regional circulation. Summary data from the physical model are used to advance vecto rs from resting-stock locations in Gulf of Maine basins through two generat ions to sites of readiness for return to rest. Supply of Calanus stock to G eorges Bank comes from all of the gulf and from the Scotian Shelf. The top of the bank is stocked from western gulf basins; the North-east Peak is sto cked from Georges Basin and the Scotian Shelf. All sources contribute to st ock that accumulates in the SCOPEX gyre off the north-west shoulder of Geor ges Bank, explaining the high abundance recurrently seen in that region. Th ere is some return of resting stock to Wilkinson Basin in the western gulf, but other basins must mostly be restocked from upstream sources to the nor th-east.