Geologic Controls on the Ecology of the Salish Sea
The complex geology beneath the Salish Sea results from a series of long geologic
processes including, but not limited to, plate collision and subduction, glaciation,
and sea level changes. The sculptured landscapes and seascapes created by these processes
provide unique benthic habitats for a variety of organisms critical to keeping the
inland sea of the Salish both viable and healthy. Many of the habitats are ephemeral,
constantly being altered through oceanographic and tectonic activities. For example,
dynamic bedforms created by strong tidal currents provide habitats for foraging fish,
such as the Pacific sand lance, whereas rock rubble shaken from the flanks of islands
by earthquakes forms habitat for rockfish and lingcod. Deep-sea sponge reefs trap
sediment and provide relief on an otherwise flat seafloor that in turn provide shelter
for fish and other organisms from strong seafloor currents and refuge from predation.
Seafloor exposures of bedrock and basement rocks provide hard substrate for encrusting
and sessile organisms that provide food and shelter to epifauna and fish, while organic
and fine-grain clastic sediments fill bays and sounds creating substrate for eelgrass
and other shallow water vegetation that provide recruitment habitats for a multitude
of organisms. All of these geologic processes have been studied in detail with the
use of up-to-date seafloor imaging technology that reveals the seafloor in great
detail. These images and the conclusions derived from them will be presented in an
illustrated hour-long talk sponsored by the Jefferson Land Trust’s Geology Group.
Gary Greene is currently the Director of the SeaDoc Tombolo Mapping Lab on Orcas
Island WA. He also holds positions at the Friday Harbor Marine Laboratories (UW)
and the Moss Landing Marine Laboratories (SJSU). Dr. Greene obtained his Ph.D. in
Marine Geology from Stanford University in 1977, and has B.Sc. in Paleontology from
Long Beach State University and M.Sc. in Geophysics from San Jose State University
(CA). Since then has had a long and varied career as a professor, research scientist,
and manager. He has authored over 300 publications and has his professional sea
legs, having participated in over 250 marine cruises.
Dr. Greene’s lecture will start at 4 pm on Saturday, November 15 at the Quimper Unitarian
Universalist Fellowship, 2333 San Juan Avenue, Port Townsend. The talk is free and
open to the public, although a donation of $5 would be appreciated to defray expenses.
For more information, contact Michael Machette (email@example.com) or visit our
web site at www.quimpergeology.org.