Lucille and the NOAA Fisheries AUV team, together with partners from NOAA’s National Marine Sanctuaries, are searching for deep water corals in Bodega Canyon, an undersea feature located north of the Cordell Bank National Marine Sanctuary off the coast of northern California.
Dr. Elizabeth Clarke (Senior Scientist at the NOAA Fisheries NWFSC)
Dan Howard (National Marine Sanctuaries)
On day four we tried to get a deep dive at the bottom of the Bodega Canyon but weather conditions were marginal for such a deep and long dive, so we moved to an area that could help refine regional habitat maps and dived at 300 meters in an area described by Guy Cochrane (U.S. Geological Survey) as a mid-shelf anticline.
Current habitat maps indicated a hard bottom area surrounded by softer sediments of the outer shelf. The bottom turned out to be mostly soft, mixed substrate with scattered cobble/boulder habitat. In areas with hard substrate, the rocks were covered with an assortment of invertebrates including crinoids, sea cucumbers and brittle stars. Dungeness or market crabs were common on the soft bottom habitat.
Given the offshore location and exposed nature of the dive site, we were very pleased to complete four dives during our six working days. While we were in port for weather and equipment testing, we were able to look at the data we collected during the four dives. The photographs showed some scattered corals at the Bodega Canyon and Cordell escarpment along with several sponges on the limited hard substrate. It is apparent that even small isolated patches of hard substrate provide important habitat for invertebrates and fishes in this area.
Dr. Elizabeth Clarke (Senior Scientist at the NOAA Fisheries NWFSC) Dan Howard (National Marine Sanctuaries)
We have completed three successful dives so far in three days operations on the National Marine Sanctuaries research vessel, the R/V Fulmar. Lucille, the AUV, has performed very well. We dived on three different sites. The first was at the northwest edge of Bodega Canyon and the second site was at the southeast edge of Bodega Canyon. From these dives it is apparent that the Canyon is primarily sediment rock and rubble. This mud-draped area does not have any corals while there are some scattered sponges. Guy Cochrane of the U.S. Geological Survey has already used these data to refine his habitat map. Today, we moved to the slope southwest of Cordell Bank and this area also is mud draped with scattered outcrops of sedimentary rock. There were soft corals (Anthosmastus ritteri) on exposed rock. Tomorrow we are planning a dive in deeper areas toward the mouth of the Canyon.