Noxious Gas from the Mouth of Hell…

The hidden world of salps

OFF THE ANTARCTIC PENNISULA—Biologists Larry Madin (WHOI) and Patricia Kremer (U. Connecticut) led a month-long cruise in January 2006 aboard the ice-strengthened ship L.M. Gould to learn more about a little-known species of salps, a gelatinous, tube-shaped planktonic animal that may be getting more numerous in the Southern Ocean. Changes in the climate and sea ice around Antarctica may create conditions in which salps thrive instead of krill, a critical food for penguins, seals, and whales. Researchers used net sampling, scuba diving, lab experiments, and a prototype imaging instrument (LAPIS) to study salps’ feeding, reproductive biology, and ecosystem impacts. See Dive and Discover. (Photo by Brenna McLoud, Trent University, Ontario)

A titanic struggle of tiny plants

ROSS SEA—WHOI marine geochemist Mak Saito joined an international team of researchers aboard the icebreaker Nathaniel B. Palmer in the austral summer of 2005-06 to explore the ecological struggle between two major groups of algae: diatoms and phaeocystis. The team studied the algae and a number of elements in seawater that algae need to survive: carbon, nitrogen, phosphorus, iron, and cobalt. Because the algae have different nutritional preferences, the scientists hypothesize that changes in seawater chemistry will allow one group to out compete the other. The outcome has implications for climate change, because photosynthetic algae use huge amounts of heat-trapping carbon dioxide. On Jan. 14, 2006, cruise members claimed to make history by sailing farther south than anyone in recorded history, in the Bay of Whales. See CORSACS cruise. (Photo by Mak Saito, Woods Hole Oceanographic Institution)

Noxious gas from the mouth of hell

MASAYA, NICARAGUA—In the 1500s, a visiting friar looked into Masaya Volcano’s hot, smoking pit lined with rows of teeth-like rocks and dubbed it “the mouth of hell.” For WHOI geochemist Ken Sims, it is a laboratory. Most experts in volcanic gases work atop crater rims. But Sims, who visited Masaya in March 2006, possesses both climbing skill and scientific knowledge to safely collect noxious gas samples directly from highly concentrated plumes in the caldera. By gathering gas samples from volcanoes worldwide, Sims is exploring how our planet is evolving and how volcanic gases cause climate changes that may even have led to the extinction of dinosaurs. See Into the Mouth of Hell. (Photo by Amy Nevala, Woods Hole Oceanographic Institution)

Is the red tide coming back in?

MASSACHUSETTS BAY—The historic 2005 “red tide” of the harmful algae Alexandrium fundyense was the most widespread and intense in New England since 1972. It kept the WHOI sampling team, led by Bruce Keafer, going to sea on coastal research vessel Tioga and other vessels through December to see if the toxin-producing plants left cysts to seed future outbreaks. Meanwhile, Deana Erdner (right), Linda McCauley, Kerry Norton, and others in WHOI biologist Don Anderson’s laboratory have been isolating and culturing cells to figure out which genotype of Alexandrium dominated the 2005 bloom. In April 2006, Keafer and crew saddled up for another season, making several trips on Tioga to see if history repeats itself. See New Maps Provide Clues to the Historic 2005 Red Tide Outbreak in New England And Hints for 2006. (Photo by Mike Carlowicz, Woods Hole Oceanographic Institution)

Exploring the ocean’s interior

SOUTHERN OCEAN—Oceans are layered with distinct water masses that vary in size, temperature, and saltiness. Researchers on the research vessel Knorr spent seven weeks in the winter of 2006 surveying the source of a dense, low-salt layer that flows north from Antarctica and fills almost all the Southern Hemisphere and tropical oceans at depths of 2,600 to 3,200 feet (800 to 1,000 meters). Still unknown is how this water mass forms, then sinks, rises, and flows, and how it affects global climate, said the expedition’s co-leader Lynne Talley, a physical oceanographer at Scripps Institution of Oceanography and a 1982 graduate of the MIT/WHOI Joint Program. (Photo by Amy Simoneau, Woods Hole Oceanographic Institution)

A density battle off the Outer Cape

CAPE COD—In winter, shallow waters off the National Seashore on Cape Cod cool and get more dense. But as snow melts in northern New England in spring, a fresher coastal current appears off Cape Cod. These two phenomena oppose each other: The winter-cooled, dense shallow waters are potentially capable of flowing offshore into the center of the Gulf of Maine; the fresher waters are less dense and more likely to travel long distances along the coast. In the winter of 2005-06, WHOI physical oceanographers Glen Gawarkiewicz and Andrey Shcherbina have investigated the water masses off Cape Cod, using a combination of observations from a REMUS autonomous underwater vehicle, moored current profilers, and hydrographic measurements from WHOI’s coastal research vessel Tioga. See Outer Cape Cod Winter Cooling Project. (Photo by Chris Linder, Woods Hole Oceanographic Institution)

Alvin’s last ride; Sentry’s first

SARGASSO SEA—After six months of maintenance, the deep-sea submersible Alvin is returning to work. In April 2006, the sub’s engineers and pilots made recertification dives, submerging first in shallow waters then deeper to Alvin’s maximum 14,700-foot (4,500-meter) depth. On the same expedition on R/V Atlantis, engineers conducted the first deep-water dunks of the new autonomous vehicle Sentry (below). The fast-moving, four-winged vehicle—slightly smaller than a Volkswagen Beetle—will perform sonar surveys over rugged undersea terrain. Trials allow engineers to see how Sentry handles navigating and maneuvering at depths of 16,400 feet (5,000 meters). See Alvin. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)