Johnson, C.L.1, J.M. Pringle2,
and C.S. Chen3
1Department of Engineering Math, Dalhousie University,
Halifax, NS, Canada B3J 2X4
2Scripps Institution of Oceanography, University of
California, San Diego, La Jolla, CA 92032
3School for Marine Science and Technology, University of
Massachusetts-Darmouth, New Bedore, MA 02744-1221
Population growth of the copepod Calanus finmarchicus on
Georges Bank is seeded in part by individuals that emerge from
dormancy in the southern Gulf of Maine (GOM) and are then
transported onto the Bank. Processes that affect the transport and
retention of dormant C. finmarchicus in the GOM may therefore
have an important influence on population dynamics and availability
of early copepod stages as prey for larval fish on the Bank. A
three-dimensional, particle-tracking circulation model (FVCOM
GOM/GB) is used to estimate retention times of C.
finmarchicus in the GOM and transport pathways both within the GOM
and between the GOM and slope water. The inter-annual variability
of the retention times and transport pathways is estimated from the
variability in the physical forcing of the ocean. The timescales of
physical retention in the GOM are compared to the timescale of
dormancy to determine whether C. finmarchicus seeding Georges
Bank are primarily endogenous to the GOM or are transported into the
GOM from elsewhere, and the simulations of inter-annual variation in
the transport pathways are used to discover how climate variability
influences sources of C. finmarchicus to the Bank.
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