HR: 11:20h
AN: OS12A-05    [Abstracts]
TI: Tidal Mixing and Buoyancy Advection: Joint Influences on Lobster Distribution in Coastal Maine
AU: * Brooks, D A
EM: dbrooks@ocean.tamu.edu
AF: Texas A&M University, Department of Oceanography, College Station, TX 77843 United States
AB: The Eastern Maine Coastal Current (EMCC) flows southwestward from the mouth of the Bay of Fundy to Penobscot Bay on the central Maine coast. Maximum non-tidal surface speeds reach 20-30 cm/s about 20 km offshore during April-May when the outflow from the Saint John River is strongest. Vigorous tides cause strong vertical and horizontal mixing, so that dispersal of neutral particles is influenced both by advection and tidal mixing. To survive, planktonic lobsters carried southwestward in the surface flow must settle to a nearshore cobble substrate. Larvae hatched near the Bay of Fundy can be advected to the central coast in 2-3 weeks, roughly the time needed to reach settlement stage. Over the same period, transverse tidal mixing is sufficient to raise nearshore larval concentrations to about half that offshore in the axis of the EMCC. Both processes may be necessary to explain the observed lobster distribution, which exhibits a distinct maximum in the central coastal region. The seasonal development of the EMCC is also influenced by winds and the larger circulation of the Gulf of Maine. This work is part of a multidisciplinary synthesis study funded by the NOAA Coastal Ocean Program.
DE: 4805 Biogeochemical cycles (1615)
DE: 4815 Ecosystems, structure and dynamics
DE: 4863 Sedimentation
DE: 4219 Continental shelf processes
DE: 4235 Estuarine processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting