Clarke and Fruh 2010

technical report |

A characterization of the sponge community in the region of Grays Canyon, WA from a survey using an autonomus underwater vehicle, October 2010

Clarke ME, Fruh E


Areas with high concentrations of glass sponges described as “reefs” recently were discovered associated with methane bubble plumes at Grays Canyon on the Washington State margin and a subsequent survey indicated that this is a particularly rich area with large numbers of associated fish and euphausids (Johnson 2008, 2009). Previously, large concentrations of glass sponges in the northwest Pacific were only known to occur only off British Columbia (e.g. Conway et al. 1991, 2001, 2004, 2005; Cook 2008). Oceana proposed in May 2009 to the Pacific Fishery Management Council (PFMC) that this newly discovered site receive additional protection under Essential Fish Habitat (EFH) mandates (Oceana 2009). However, the extent of these sponge areas off the Washington Coast had not been identified and the sponge and fish communities had not been quantified. Current EFH Conservation Area boundaries do not include the sponge reef site and many of the previous records of sponges detailed by Oceana are not within current EFH Conservation Area boundaries (Figure 1). The PFMC declined to take action in 2009 citing the need for more information about the area to enable appropriate protections and regulations to be put in place.. The goals of this project are to: 1) Examine the extent of the sponge reef identified in 2007 and proposed for protection by Oceana in 2009 2) Describe the associated ecosystem to assist in determining this area’s role as EFH; and 3) Provide the PFMC with additional information to assess any actions that may be needed to protect the Grays Canyon sponge area. Targeted habitats for this work were soft bottom and moderately rocky habitat offshore of Grays Harbor, WA. The primary survey site was centered at the glass sponge site already identified by Paul Johnson (Johnson 2008, 2009). The SeaBed AUV, Lucille, was used to conduct photographic surveys of macro-fauna, including invertebrates and bottom fish in order to determine the species composition and density of sponges and associated fish fauna.

Depth range
144- 169 m

Mesophotic “mentions”
0 x (total of 7934 words)

* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'
* Focused on 'temperate mesophotic ecosystem'

Community structure
Management and Conservation

Porifera (Sponges)
Scleractinia (Hard Corals)

USA - Continental Pacific Ocean

Autonomous Underwater Vehicle (AUV)

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