Showing posts with label sea anemone. Show all posts
Showing posts with label sea anemone. Show all posts

Monday, November 05, 2007

Divers Find New Species In Aleutians


There are unknown creatures lurking under the windswept islands of the Aleutians, according to a team of scientific divers from the University of Alaska Fairbanks।


This summer, while completing the second phase of a two-year broad scientific survey of the waters around the Aleutian Islands, scientists have discovered what may be three new marine organisms. This year's dives surveyed the western region of the Aleutians, from Attu to Amlia Island, while last year's assessment covered the eastern region.
During the dives, two potentially new species of sea anemones have been discovered। Stephen Jewett, a professor of marine biology and the dive leader on the expedition, says that these are "walking" or "swimming" anemones because they move across the seafloor as they feed. While most sea anemones are anchored to the seabed, a "swimming" anemone can detach and drift with ocean currents. The size of these anemones ranges from the size of a softball to the size of a basketball.


Another new species is a kelp or brown algae that scientists have named the "Golden V Kelp" or Aureophycus aleuticus. According to Mandy Lindeberg, an algae expert with NOAA's National Marine Fisheries Service and a member of the expedition, the kelp may represent a new genus, or even family, of the seaweed. Up to ten feet long, the kelp was discovered near thermal vents in the region of the Islands of the Four Mountains.
"Since the underwater world of the Aleutian Islands has been studied so little, new species are being discovered, even today," said Jewett. He adds that even more new species may be revealed as samples collected during the dives continue to be analyzed.
The organisms were found while surveying more than 1000 miles of rarely-explored coastline, from Attu to the Tigalda Islands. Logging more than 300 hours underwater, the divers collected hundreds of water, biological and chemical samples during 440 dives. Armed with underwater cameras and video cameras, the divers took hundreds of photographs and dozens of short movies of the creatures that inhabit the coast of the Aleutians.
According to Jewett, the scientists are reasonably sure that the kelp is a new species, but more work is being done to confirm that the sea anemone species are completely new to science. Correspondence with anemone experts has so far shown the anemones to be new species, but the analysis is ongoing.
During both years, the chief scientist on the project was Douglas Dasher, a water quality expert from the Alaska Department of Environmental Conservation. The scientific team operated from the R/V NORSEMAN, a 108-foot vessel originally designed for crab fishing in the Bering Sea.
The dives were part of a broad health assessment of the Aleutian Islands and were sponsored by the Alaska Environmental Monitoring and Assessment Program, also referred to as AKMAP. The program is funded by the Environmental Protection Agency and managed through a joint agreement between the ADEC and UAF.
Samples from the dives are being used to catalog biodiversity in the region, assess water quality and potential contaminants। According to Jewett, this is the first time the remote nearshore region of the Aleutian Chain has undergone an in-depth marine assessment.


Not immune from human impacts
The rugged and remote islands of the Aleutians are not immune to the reach of human activity, say scientists leading the expedition.
"Pollutants traveling through air and water pathways from temperate latitudes have been showing up in the area," says Jewett. "Debris and spills from World War II in the Aleutians have left their mark behind in unexploded ordinance and local sources of pollutants."
Scientists on the project are using water and tissue samples collected during the dives to gauge the impacts of human activity in the area. Samples are being tested for nutrient and oxygen levels in the water, acidity, temperature and radioactive chemicals left over from the underwater nuclear tests conducted at Amchitka Island between 1965 and 1971.
"Climate change, with changes in water temperature, wind patterns and currents may impact the region's biological life," added Jewett. "It is important that we collect this information before any major changes occur."
Jewett, Dasher and the other scientists on the expedition hope that this assessment will help scientists gauge the overall health of the Aleutian Islands, both to provide a baseline for future comparison and to provide a general evaluation of the region's marine conditions.
A unique diving experience
Diving to a maximum depth of 60 feet along 1000 miles of mostly uninhabited coastline is an extraordinary experience, says Jewett.
"This is my fourth diving mission in the Aleutians," said Jewett. "In my view, it's the best cold-water diving experience in the Northern Hemisphere, because of the outstanding visibility, coupled with the diverse and colorful marine life."
Selected images from the dives can be seen at http://www.sfos.uaf.edu/emap
UAF divers on the expedition included Reid Brewer, marine advisory program agent in Unalaska; Max Hoberg, marine taxonomist; Heloise Chenelot, research technician; and Shawn Harper, a graduate student studying marine biology. ADEC scientists included Jim Gendron, Terri Lomax and Nic Dallman. Other members of the scientific team included Roger Clark, a marine taxonomist with NOAA, and Roger Deffendall, a volunteer diver from Unalaska.
The Aleutian Islands dives support the National Coastal Assessment Program, a nation-wide project to characterize the U.S. nearshore coastline. AKMAP methods provide a practical, cost-effective system to characterize Alaska's coastal and surface waters. The AKMAP team has already sampled the marine waters off of Alaska's southcentral and southeastern coasts. The western Aleutians section of the program is the fourth of five planned surveys to assess Alaska's entire coastline.
Adapted from materials provided by University of Alaska Fairbanks।

Thursday, May 17, 2007

New Species Of Sea Anemone Found In Deepest Pacific


Researchers cruising for creatures that live in the deepest parts of the Pacific Ocean found a new species of sea anemone living in the unlikeliest of habitats – the carcass of a dead whale।

A marine biologist would say that discovering a new sea anemone isn't so unusual. But finding one that calls a dead whale home is what sets this new creature apart.
Since the scientists who initially found these animals weren't sea anemone specialists, they sent the 10 specimens they collected to Meg Daly, an assistant professor of evolution, ecology and organismal biology at Ohio State University . Daly runs one of the very few laboratories in the world equipped to study sea anemones.
“These creatures were so cool simply because we knew that no sea anemone had ever been found on a whale fall,” she said.
Once a whale dies, its carcass sinks to the bottom of the ocean. Scientists call this a “whale fall.” The anemones that Daly received once lived on the bones of a dead whale some 1.8 miles (3,000 meters) below sea level in a region of the Pacific Ocean called Monterey Canyon, roughly 25 miles off the coast of Monterey, Calif. All of the specimens currently in Daly's collection came from this whale fall.
The anemone, given the scientific name Anthosactis pearseae – there is no English name for it – is small and white and roughly cube-shaped. It's about the size of a human molar, and even looks like a tooth with small tentacles on one side.
Daly and Luciana Gusmão, a doctoral student in Daly's laboratory, describe A. pearseae in detail in a recent issue of the Journal of Natural History. The two assigned the anemone to the genus Anthosactis primarily due to the roughly uniform length of A. pearseae's tentacles – a characteristic common to this group of about seven sea anemones.
“We tend to differentiate Anthosactis species from other groups of sea anemones by a variety of traits, rather than any one unique attribute,” Daly said.
She and Gusmão named A. pearseae after Vicki Pearse, the naturalist who first collected the specimens during a cruise of the Monterey Bay Aquarium Research Institute's research vessel the Western Flyer. Pearse is a research associate at the Institute of Marine Sciences at the University of Santa Cruz.
It's customary to name a newly discovered plant or animal species after the person who found it, or after the place where it was discovered.
Collecting deep-sea creatures is a tedious process that involves a lot of high-tech equipment like underwater video cameras attached to remotely operated vehicles (ROVs). Deep sea ROVs are also equipped with robotic arms and suction devices that are used to collect species.
“It's like a submarine that's manned from the surface,” said Daly, who plans to head to Monterey Canyon later this year in hopes of finding more dead whales with A. pearseae roosting on the bones. A successful trip could answer some of Daly's lingering questions about the species itself and, more broadly, may provide clues on how human activities affect this unique, seemingly removed ecosystem.
“The thing about these communities is that they seem so ephemeral and so unplanned,” Daly said. “A whale dies where it dies, and its carcass lands wherever. But these are actually some of the most stable deep sea communities.
“A better understanding of deep-sea populations may shed light on how humans drive ecological change, whether it's through whaling or global climate change,” she said, and also pointed out that there are now far fewer major whale migrations along the California coast.
While the flesh of a dead whale decomposes within weeks, the bones can last anywhere from 60 to 100 years.
“As that happens, the bacteria that break down the bones release sulfur,” Daly said. “A whole community of aquatic creatures uses that sulfur to make energy, much like plants convert light into energy.”
Daly doesn't know much about A. pearseae beyond its physical description. She and Gusmão aren't sure how old the creatures are, and say that sea anemones can live for hundreds of years. Nor are they sure how A. pearseae reproduce (each anemone may have male and female sex organs), or if it lives exclusively on whale carcasses.
“So far, a single dead whale is the only place where we've found these anemones,” Daly said.
She and Gusmão plan to include A. pearseae in a long-term evolutionary study of genetic relationships among sea anemones. A. pearseae belongs to an extremely diverse group of anemones, Daly said, and comparing the anemones' genetic sequences may clue the researchers in to how the different species evolved over time.
Note: This story has been adapted from a news release issued by Ohio State University.