Benthopelagic coupling: Krill at the edge of Monterey Canyon
Project Manager: William M. Hamner
Lead Scientist: William M. Hamner, George Matsumoto, Bruce Robison
Lead Engineer: Dan Davis

Whales, fish and seabirds congregate in late summer above the 200 m isobath along the southeast edge of the Monterey Canyon to feed on patchy schools of krill that remain trapped by these predators at the surface during the day. Downstream enrichment from the Santa Cruz Front supports high densities of euphausiids in Monterey Bay, but distant upwelling alone cannot explain the spatially stable location of krill or pelagic predators for months above the 200 m isobath on the southeast edge of the Monterey Canyon. Furthermore, krill are vertical diurnal migrators and most krill during the day aggregate at depths of about 150 m on the shelf break or further seaward above the deeper parts of the canyon as part of the Deep Scattering Layer. Deep water aggregations of krill occur because of down-shelf migration by krill displaced inshore during the night by southeast surface currents or by up-shelf flow of krill in the deep-scattering layer during the day. Meetings will be held with MBARI staff during 2002 to discuss how best to leverage off some of existing current measurement programs underway at MBARI.