Re-discovering Cordell Bank:
Dive Expedition 30 Years Later

Over thirty years have passed since the initial exploration of the upper pinnacles of Cordell Bank by SCUBA divers from the non-profit organization Cordell Expeditions. For the first time since the designation of the Cordell Bank National Marine Sanctuary (CBNMS) in 1989, technical scientific SCUBA divers will revisit the shallowest parts of Cordell Bank's reef crest (115-200ft) from October 6-11th, 2010 off of the research vessel Fulmar.

Cordell Bank National Marine Sanctuary is about 50 miles northwest of San Francisco. Click here for a larger map. (NOAA)

Cordell Bank, the main feature of CBNMS, is located on the continental shelf, about 50 miles northwest of the Golden Gate Bridge and 20 miles west of the Point Reyes lighthouse. The bank is 4.5 miles wide by 9.5 miles long and emerges from the soft sediments of the continental shelf, with the upper pinnacles reaching to within 115 feet of the ocean's surface. The upper reef crests of Cordell Bank are carpeted in lush invertebrate cover, including hydrocorals, stony corals, sponges, anemones, hydroids, macroalgae and tunicates, providing critical habitat to a variety of first-year juvenile and adult rockfish species. Cordell Bank is truly a biologically diverse and unique place.

Location of dive locations for the 2010 expedition. Click here for a larger map. (NOAA)

Mission Objectives:

The central goal of the Cordell Bank Reef Crest mission is to test the feasibility of using technical divers for accomplishing hands-on tasks at depths of 115-200ft over Cordell Bank. What will the composition of the animal community look like? Will we see changes from the historic Cordell Expedition diver's observations and the specimens they collected?

To address these and other questions the divers will:

• Use high definition cameras to collect video and still images of the reef crest invertebrate and fish communities so that we can better understand abundance and distribution patterns.
• Collect specimens to be identified and archived in the Cordell Bank collections at the California Academy of Sciences (CAS). Of particular interest are target tunicates for identifying a potential invasive species and target hydrocoral (Stylaster sp.) for species identification and reproductive analyses.
• Dive on locations of the bank that have not been previously surveyed and revisit some of the Cordell Expedition's locations surveyed in the 1970s and 1980s.

Completing these objectives will provide multi-faceted information about the current Cordell Bank reef crest ecosystem. The diver's surveys will show us how the invertebrate and fish communities look and compare to historical conditions, if the communities have changed in response to various pressures, including climate change and ocean acidification, or if they have benefited from a recent fishing closure prohibiting the use of bottom contact fishing gear over the bank. This information will help inform sanctuary management on priority conservation science needs for the future to best protect this unique and vital jewel in the Pacific.