The combination of techniques proved effective at following water patches and plankton populations within them for periods of up to five days as they circulated and dispersed along the flanks of the bank. The surface layer experiment on the South Flank, showed an example of wind-driven transport across the front and onto the crest under easterly winds. The surface waters were rich in hydroids and very poor in Calanus, while the pycnocline was rich in Calanus.
The pycnocline experiment on the South Flank included some surface drifters, which again showed transport toward the crest. The dye patch and drifters in the pycnocline showed mostly along-isobath flow, but with eddy dispersion toward the front. The dye release was performed in a strong patch of Calanus, which, however, nearly disappeared at the end of the experiment upon the arrival of large schools of herring, mackerel and whales.
In the experiment on the North Flank, the drifters gave various results on flow toward the tidal mixing front. Again, the dye patch moved primarily along isobaths. Just below this patch was an abundant population of the colonial diatom Chaetoceros socialis, concentrated in a thin layer at the base of the pycnocline and extending into the deep mixed layer.
The experiments promise to improve our understanding of the transport of plankton toward and across the tidal mixing front, both in the surface layer and in the pycnocline. The drogue and dye data shold give quantitative estimates of mixing and transport parameters, and the VPR observations will help to assess the extent to which such activities as swimming and predation add to fluid motions in determining plankton populations and fluxes. These results will ultimately be of use in coupled bio-physical models of the ecology of coastal banks.