Pacific Northwest glass sponge reefs
Research cruises resulted in the discovery of glass sponge reefs, methane bubble streams, and dense swarms of krill in Grays Canyon, spurring large-scale geological research investment in the area.
Paul Johnson, University of Washington, School of Oceanography
Beginning in 2007, Washington Sea Grant (WSG) supported three research cruises to this geologically and biologically important area.
In 1987, reefs of glass sponges — organisms long thought to be extinct — were discovered off the coast of British Columbia. Because similar environmental conditions exist on the continental shelf by Grays Canyon, scientists hypothesized that similar sponge colonies might be found in other areas off the Washington coast.
The cruises located, mapped, and sampled extensive areas of both live and relict glass sponge reefs at the continental margin. In the same vicinity, they discovered “pockmarks,” methane bubble plumes venting from small mud volcanoes, and other geological features. These areas also turned out to be biological hotspots, supporting massive swarms of krill, along with predator fish and orca whales. Their discovery raises questions about possible links between high marine productivity and methane bubble plumes that have yet to be fully investigated. WSG’s investment in the initial research leveraged more than $10 million in National Science Foundation funding for three ship-based geological projects: the Cascadia Ocean Bottom Seismic Initiative Pool (OBSIP) to examine seismic hazards in the Cascadia subduction zone; a 2012 study to image the subduction zone and hydrate deposits on the margin; and a study to assess the thermal structure of the “locked zone” of the Cascadia megathrust.