Dive and Discover : Expedition 1 : Daily Updates

Daily Update: Dive 3520
January 17, 2000
By Dr. Dan Fornari and Dr. Susan Humphris

Today is “hump day”! We are halfway through the cruise! To celebrate, we ate homemade pizza for dinner. The weather is still calm and sunny - perfect for launching and recovering Alvin. We even had a visit from a small pod of pilot whales, but because they came just before Alvin surfaced, we could not go out in the Avon to observe and record them. We'll try again tomorrow.

On board the ship, day and night seem to run together. Some people get on a “Night Owl” schedule, working during the night and sleeping during the day. Many people processed samples into the early morning hours. Once Alvin was launched, some went to bed.

Some people also took the opportunity to get some exercise. Susan Humphris led an aerobics session on the bow.

The scientists continued to process the biological samples Alvin had collected. They are trying to learn how these vent animals in Guaymas Basin survive and how they differ from the vent animals found on the mid-ocean ridge crests in the Pacific and Atlantic Oceans. For example, both the vents in Guaymas Basin and the vents on the Juan de Fuca Ridge off the coast of Oregon and Washington support tubeworms, clams, polychaete worms, and octopi. However, the scientists have determined that of the 50 or so vent species that live in Guaymas Basin, only five live along the Juan de Fuca Ridge.

Tim Shank, Bob Feldman, and Luis Hurtado are extracting DNA (deoxyribonucleic acid) from the clams and tubeworms, and from the bacteria found living inside the tubeworm’s cavity or trophosome. To do so, they dissolve pieces of tubeworm and clam tissue and samples of bacteria in solutions inside test tubes. They freeze the remaining tubeworm and clam tissues at -70°C to preserve them in case someone needs to extract DNA in the future.

This research has two goals. First, Tim, Bob, and Luis plan to compare the genetic “fingerprints” of clams, tubeworms, and symbiotic bacteria living in Guaymas Basin to those of tubeworms, clams, and symbiotic bacteria living around other hydrothermal vents throughout the world. By comparing “fingerprints,” they hope to determine how closely related the animals and microbes in Guaymas Basin are to those in other hydrothermal vent communities.

Sunday was not all work, however. That afternoon Pat Hickey spotted a school of young yellow-fin tuna swimming around the stern. Several people tried to catch them, but only Pat succeeded. The tuna he caught was only 18 inches long, so he let it go.

Their second goal is to determine how much damage there is to the animals’ DNA. Guaymas Basin vents differ from most of the world’s other vents because the vent fluids must pass through almost 400 meters (about 1200 feet) of sediments before reaching the seafloor. Over millions of years, the scalding hydrothermal fluid converts the organic matter in these sediments to petroleum or oil products (hydrocarbons). These chemicals cause cancer in almost all living things on Earth. However, scientists have so far seen no signs of cancer (such as tumors) in the tubeworms, clams, or fish living in Guaymas Basin. Somehow, the organisms in Guaymas Basin have adapted to living in these toxic conditions. Scientists now know that almost all cancers start when DNA is damaged within an animal’s cells. Perhaps these animals have unusual adaptations that prevent them from getting sick with cancer. Perhaps these adaptations can provide clues that will help medical researchers find a way to prevent or even cure cancer in people. Tim, Bob, and Luis hope to find out.

Dive Summary
On Bottom: 0932 hrs
Off Bottom: 1509 hrs
Maximum Depth: 2005 m

The primary objective of today’s dive was to collect more chemical and temperature scans and take “Sipper” samples from the vents that have been found during the past week. Barbara Campbell and Brian Glazer also collected sulfide samples from spongy beehive vents. The microbiologists will use these samples to culture microorganisms. When scientists from different fields, such as chemistry and microbiology, join forces to solve a science problem, it’s called multi-disciplinary research.

Unfortunately, Pilot Bruce Strickrott had to solve some carbon dioxide scrubber problems during the dive. They also used a lot of power driving around the seafloor, so they could not get through all of their objectives. But in the middle of the dive they had one surprise. A large spider crab (with a 12-cm diameter body and legs that stuck out nearly as much) made the mistake of showing itself. Bruce snatched it off the bottom and brought it back for the biologists to analyze. It was a female and carried many black eggs on its underside.

All things considered, Barbara and Brian had a successful first dive in Alvin and an experience they'll never forget. They too had the ritual baptism with cold seawater once they got back on board. They also had their shoes filled with whipped cream!