Note: You need to enable scripting and Javascript in your browser settings to best view and navigate our website. Otherwise, use our keyboard navigation and search page. For keyboard tabbing on this page you can bypass the top menu bar navigation and jump to the page sidebar navigation (if applicable), or jump to the page body. Our print link for screen media is scripted. Your computer's normal print command will print this page. Please contact us if you have difficulty in accessing our web pages.

Home
Site map
Contact us
Print printer

Mobile users can use the Site Map to access the principal pages

2002 Gulf of Alaska Seamount Cruise with the DSV Alvin

RACE Home

RACE Shellfish Assessment

Kodiak Laboratory
  Current Research
  EBS Crab Survey
  Photo Gallery

Pathobiology
Current Research
Team Contacts

Publications

Posters

Quarterly Reports-Crab

Sitemap

On Thursday, June 20, 2002, Dr. Bradley Stevens joined the R/V Atlantis, mother ship for the Deep Submergence Vehicle (DSV) Alvin, operated by the Woods Hole Oceanographic Institute. On this expedition, with the DSV Alvin, they studied the geology, microbiology, and ecology of deepwater crabs, corals, and other life on undersea mountains called seamounts, in the Gulf of Alaska. They visited six seamounts, five of them previously unexplored. These seamounts are: Patton, Murray, Chirikof, Campbell, Marchand, Scott, and Warwick. Dr. Stevens had the opportunity to dive on both the Patton and Murray seamounts. His dive impressions are worth a visit as well.

Full-coverage bathymetry maps were made of all six seamounts visited by the R/V Atlantis. SeaBeam surveys of the seamount bathymetry were conducted at night, leaving the days for Alvin dives. Other objectives of Alvin's research on the seamounts were to: define the distribution of crab species with depth, associate crab species and their life history stages with substrates, examine dispersion patterns of crab species, collect crabs for life history information and culture, collect basaltic rocks for aging seamounts, make opportunistic biological and geological observations, collect soft coral samples for genetic studies, and to collect water and sediment samples for the study of bacteria.

Ship support by the R/V Atlantis is vital for the successful operation of the Deep Submergence Vehicle (DSV) Alvin, operated by the Woods Hole Oceanographic Institute. The Alvin can hold three passengers, typically a pilot and two scientists, in its 23 feet, 4 inches; cruise at a maximum speed of 2 knots; operate to a depth of 14,764 feet; and support its passengers for 216 man-hours(72 hrs by 3 persons).

On June 26, 2002, Dr. Bradley Stevens made his first dive of the summer, a descent onto the Murray seamount to a depth of 2700 meters. The word that day was, "Go deep or go home." On the bottom, he observed spider crab, Macroregonia macrochira, walking through marine snow, the leftover remains of dead and decaying matter that once lived in the surface waters. The biology of the spider crab is poorly known even though they are the most common species, and only brachyuran observed below 1000 m. Either with Alvin's manipulators or the baited trap on an elevator, 28 specimens were captured and then placed in a tank of chilled seawater.

At 325 meters bamboo coral, an isidid coral and brittlestars (opiuroids) were seen. The Bamboo coral is made of both calcium carbonate (white "legs") connected by proteins (black "joints"). Yellow crinoids were abundant from 583 meters to the top of the seamount at about 300 meters. Chirostylus sp. (red pinchbug) were also collected on the Murray Seamount at 760 meters. At depth, in their habitat, they were seen hanging on hydroid colonies, "holding their chela like angry gorillas."

One goal of the Gulf of Alaska Seamount study was to collect the different corals and invertebrates found on the different seamounts, and to document their depth distribution and community structure. Dr. Amy Baco-Taylor was collecting soft corals for her genetic research, and tells more in her Ocean Explorer web article, Dispersal and Reproductive Biology of Deep-Sea corals. The skeleton of "Bamboo coral" and ophiurids or brittlestars shown here were examined in the lab aboard the R/V Atlantis. These specimens were collected at the Murray Seamount.

Rocks were collected on five dives for microbiological studies and for samples to determine their volcanic histories. The Alvin manipulator placed the rocks in an isolation box, designed to minimize contamination of the rocks with surface water and to hold the rocks in their ambient sea water until they were transferred to sterile containers on deck. Future analysis of these microorganisms will tell the amount and kinds of bacteria that live within deep sea volcanic rocks. Microbes in these deep sea rocky environments may be some of the most primitive on Earth because of their potential ability to survive on a diet of rocks and water. This large basket with plastic fingers worked well for holding large crabs on Alvin's science tray, although smaller specimens sometimes escaped or washed out, particularly at the surface.

NOAA's Ocean Explorer Explorations has more Alaska Seamount Information and images. Or visit: National Geographics, "Reporter's Diary: Diving in a Deep-Sea Sub." Some text for this article was excerpted from Gulf of Alaska Seamount Exploration Cruise Report, June 22-July15, 2002.

Webmaster | Privacy | Disclaimer | Accessibility