OREGON STATE UNIVERSITY

hatfield marine science center

Scientists still following far-ranging Varvara as Russian whale returns

NEWPORT, Ore. – After visiting three different lagoons in the Pacific Ocean side of Baja Mexico, a rare western gray whale named “Varvara” is migrating up the West Coast – presumably en route to her home range near Russia’s Sakhalin Island.

The Mexican lagoons are known calving and breeding grounds for eastern gray whales and Varvara may have gone there in search of a partner, scientists say.

“She did not calve for sure, or she would have stayed in one place for four to eight weeks because the calves need to gain strength, coordination and blubber – for fuel and insulation,” said Bruce Mate, director of the Marine Mammal Institute at Oregon State University. “More likely, she would have been breeding this year and spent time around three areas where that activity is commonly seen.”

By Friday, the 9-year-old female was near the Washington/Canadian border, traveling northward at a rate of up to 100 miles a day.

There is “great interest” in Varvara’s journey in Tofino, the whale watching hub on the west coast of Vancouver Island, according to Jim Darling of the Pacific Wildlife Foundation, who has studied whale populations for years.

“Many have been following each update on Varvara since she passed on her southward trek last January,” Darling said. “Among the many things Varvara and Flex have taught us is the potential for intermingling between the western and eastern gray whales – not only on breeding grounds, but during migrations and spring feeding aggregations along the way.”

The public can follow the travels of Varvara online at: http://mmi.oregonstate.edu/Sakhalin2011

The long-distance journey of Varvara – which means Barbara in Russian – is critical because this is the first time scientists have documented that critically endangered western gray whales travel to Baja Mexico, where eastern gray whales frequent. Western gray whales are thought to be genetically distinct from their more populous cousins that are common up and down the West Coast, but Varvara clearly was mingling with eastern gray whales.

Mate said there are only about 130 western gray whales in the world and the behavior of Varvara has significant ecological and management implications.

“Clearly the experience of Varvara, and Flex before her, demonstrates that western gray whales can and do come over to the eastern Pacific,” Mate said. “Whether this suggests that they are not a distinct population or that we underestimated their range isn’t yet clear.”

Last year, American and Russian scientists teamed up to follow “Flex,” a 13-year-old western gray whale that journeyed across the Bering Sea and North Pacific Ocean to Vancouver Island and down to Oregon before the tag finally quit working. The scientists returned to Sakhalin Island last fall to tag a half-dozen western gray whales and this time one of the tags, on Varvara, lasted all the way through her journey to the Sea of Cortez and is still transmitting – some 8,000 miles later.

“The average tag survives 123 days,” said Mate, who works out of OSU's Hatfield Marine Science Center, “and this one is still working. Hopefully it will last so we can see if Varvara takes the same route back to Russia, or travels through different waters.”

In the 1970s, western gray whales were thought to have gone extinct, but a small aggregation was discovered by Russian scientists off Sakhalin Island and has been monitored by Russian and U.S. scientists since the 1990s. Eastern gray whales likewise were decimated by whaling and listed as endangered, but conservation efforts led to a recovery and, at 18,000 strong, they have been delisted.

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Bruce Mate, 541-867-0202

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Varvara returns north

Study: Endangered Antarctic blue whales show surprising genetic diversity

NEWPORT, Ore. – More than 99 percent of Antarctic blue whales were killed by commercial whalers during the 20th century, but the first circumpolar genetic study of these critically endangered whales has found a surprisingly high level of diversity among the surviving population of some 2,200 individuals.

That, says lead author Angela Sremba of Oregon State University, may bode well for their future recovery.

Results of the study have just been published in the open-access journal, PLoS ONE. As part of the study, the researchers examined 218 biopsy samples collected from living Antarctic blue whales throughout the Southern Ocean from 1990 to 2009, through a project coordinated by the International Whaling Commission.

The genetic survey revealed a “surprisingly high” level of diversity that may help the population slowly rebound from its catastrophic decimation by whalers.

“Fewer than 400 Antarctic blue whales were thought to have survived when this population was protected from commercial hunting in 1966,” noted Sremba, who conducted the research as part of her master’s degree with the Marine Mammal Institute at OSU’s Hatfield Marine Science Center.  “But the exploitation period, though intense, was brief in terms of years, so the whales’ long lifespans and overlapping generations may have helped retain the diversity.”

“In fact,” she added, “some of the Antarctic blue whales that survived the genetic bottleneck may still be alive today.”

Prior to whaling Antarctic blue whales were thought to number about 250,000 individuals – a total that dwindled to fewer than 400 animals by 1972 when blue whales were last killed by illegal Soviet whaling. Blue whales are thought to be the largest animals ever to have lived on Earth, said OSU’s Scott Baker, associate director of the Marine Mammal Institute and an author on the study – and the Antarctic blue whales were even larger than their cousins in other oceans.

“These animals are very long-lived – maybe 70 to 100 years – and they can grow to a length of more than 100 feet and weigh more than 330,000 pounds,” he said. “There is a jawbone in a museum in South Africa that takes up most of the lobby. This is one reason they were so intensively exploited; they were the most valuable whales to hunt.”

Despite their history of exploitation, little is known about modern-day movements of Antarctic blue whales, which are considered a separate subspecies – differing in size and habitat use – from the smaller “pygmy” blue whales, which live in more temperate regions of the Southern Hemisphere.

Through “microsatellite genotyping,” or DNA fingerprinting, the PLoS ONE study was able to track some of the movements of individual Antarctic blue whales.

“We documented one female that traveled from one side of Antarctica to the other – a minimum distance of more than 6,650 kilometers over a period of four years,” said Sremba, who is now continuing her studies as a Ph.D. student in the Department of Fisheries and Wildlife at OSU. “It is the first documentation of individual movements by Antarctic blue whales since the end of the commercial whaling era.”

Baker said the long distance movement of a few individuals was “somewhat surprising” in comparison to the evidence for genetic differences between areas of the Southern Ocean. On one hand, it is apparent that individual Antarctic blue whales are capable of traveling enormous distances in search of food.

“On the other hand,” Baker said, “there seems to be some fidelity to the same feeding grounds as a result of a calf’s early experience with its mother. This ‘maternally directed’ fidelity to migratory destinations seems to be widespread among great whales.”

There is much, however, which scientists still don’t know about Antarctic blue whales, Baker pointed out.

“This is a poorly understood species of whales, despite its history of exploitation,” Baker said. “Only now are we developing the technology to study such a small number of whales spread across such a vast habitat.”

The biopsy samples were collected during more than two decades of research cruises supervised by the International Whaling Commission, and with international scientists joining research vessels from the Japanese Ministry of Fisheries.

Now that their population is slowly recovering, future studies may focus on Antarctic blue whales’ migration patterns, and the locations of their breeding and calving grounds.

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Angela Sremba, 541-867-0384

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Hatfield legacy lives in OSU leadership in the marine sciences

NEWPORT, Ore. – The passing Sunday of former U.S. Senator and Oregon Governor Mark Hatfield prompted an outpouring of remembrances of the political legend and his contributions to the state, including Newport, where Oregon State University’s Hatfield Marine Science Center bears his name.

Hatfield was supportive of the development of the center, which officially opened in June 1965 during his second term as Oregon governor. During his five terms as a U.S. senator, Hatfield steered critical federal funding to Newport for buildings and programs. In 1983, the center was officially named the Mark O. Hatfield Marine Science Center (HMSC).

Today, more than 300 scientists and staff members work at HMSC’s 49-acre campus. In addition to faculty researchers and students from OSU and visiting researchers from other academic institutions, the campus is home to representatives of the U.S. Fish and Wildlife Service, the U.S. Environmental Protection Agency, the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration and the Northwest National Marine Renewable Energy Center, as well as the Oregon Department of Fish and Wildlife. It is also home port for the OSU research vessels Wecoma and Elakha.

“The Hatfield Marine Science Center is a living legacy, one that will serve Oregon, Oregonians, our nation and our world for generations to come,” OSU President Edward J. Ray. “I can think of no finer tribute to Mark Hatfield's lifetime of public service.”

Ray said the scientific strengths of HMSC, which has an annual budget of more than $45 million, are a major reason why OSU is recognized as being one of the nation’s leading academic centers in marine science, with particular depth in near-shore coastal science.

“Sen. Hatfield understood the importance of the scientific work on Oregon’s coast. And he had the foresight to support a center where that work could take place and to make invaluable contributions toward the center’s expansion over three decades,” said Ray. “Without some of the groundbreaking work that came out of HMSC, climate modeling and our understanding of climate change might not have developed as quickly as it has. We might not have had the capacity to make important contributions to aquaculture science and fisheries management or the understanding of the tectonic plates beneath the Pacific Ocean. And our internationally recognized Marine Mammal Institute might not have had the impact on whale conservation around the globe that it continues to have.

“We at OSU are among many today who can say with heartfelt conviction that he will be missed.”

Images of Sen. Hatfield and HMSC are available at  http://www.flickr.com/photos/oregonstateuniversity/sets/72157627262825293/.

Hatfield Marine Science Center unveils new live OctoCam

NEWPORT – An iconic celebrity of the central Oregon coast is ready to writhe and wiggle his way onto a computer screen near you.

Oregon State University's Hatfield Marine Science Center this week unveiled its new OctoCam, streaming live video of the visitor center's resident giant Pacific octopus to the world. It can be seen at: http://hmsc.oregonstate.edu/visitor/octocam

Employing two Webcams – one outside and slightly above the tank and one inside the tank – viewers are treated to a live 24-hour show featuring the resident cephalopod interacting with tank mates and curious on-lookers. Viewers also have the option of watching archival footage of the octopus investigating the camera when it was first installed; and more archival footage will be added periodically.

The giant Pacific octopus, Enteroctopus dofleini, occupies a central spot among the visitor center's many aquatic animal exhibits. The trademark critter has been a favorite of visitors almost since OSU opened the doors to the Hatfield center in 1965. Of course, it hasn't been the same octopus; typically an adult octopus stays in the tank for between one and two years.

Younger octopuses, often donated by  local crabbers, are cycled into the tank to replace the older animals, which are then released back into Yaquina Bay to find a mate and spawn.

Many visitors plan their HMSC visits to coincide with the animal's thrice-weekly live crab feedings so they can watch this marine predator stalking and pouncing on prey while learning a bit about octopus biology and behavior. Feeding dates and times vary from season to season, and the schedule is posted on the center's website (hmsc.oregonstate.edu/visitor).

Getting the octopus on the web took the combined efforts of nearly every program at the visitor center as well as OSU Media Services. Sea Grant’s aquatic animal curator, health and husbandry specialist Dennis Glaze, had to seriously consider the feasibility of putting a camera in the octopus tank.

“Octopuses are intelligent, inquisitive, and very strong,” said Glaze. “They have the ability to take apart even the smallest mechanical component – and often will do so just to entertain themselves. Other public aquariums have had great difficulties making a project like this successful.

“Our prime concern was the health of the animal,” Glaze added, “but, of course, the survival of the camera was considered too.”

Oregon Sea Grant's marine education team has already begun using the OctoCam to put on live, interactive programs for Internet-enabled K-12 classrooms far from the Oregon coast. Marine  educator Kathryn Hawes recently used the OctoCam to do a live feeding presentation to a second grade class in Monticello, Iowa.

“None of the 20 students present had ever been to the Pacific Ocean let alone seen a live giant Pacific octopus,” Hawes said. “They were all so full of questions. This tool opens up some remarkable teaching opportunities.”

The OctoCam has been undergoing testing for a few weeks with a limited audience of HMSC employees, volunteers and supporters.

“I can't stop watching,” one fascinated tester said. “This is just the coolest thing I've ever seen on the Internet.”

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Nancee Hunter, 541-867-0357

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New Study: Parasite Causing Whirling Disease Could be Transmitted Via Fishing Waders

NEWPORT, Ore. – A new study has found that a parasite that causes deadly “whirling disease” in juvenile trout and other salmonids may be transmitted from one fishing hole to another – and from one stream to another – on fishing boots and waders.

The spread of whirling disease within the United States over the past half century has primarily been through the movement of infected fish through hatcheries, researchers say. But increasingly whirling disease has begun to show up in streams not stocked with infected fish and researchers have discovered that its transmission is not accomplished directly from fish to fish.

“The bottom line is that we’ve found that the spores that eventually infect the fish and lead to whirling disease can survive out of water for eight hours on the soles of waders,” said Paul Reno, a microbiologist with the Coastal Oregon Marine Experiment Station at Oregon State University. “In laboratory tests, we found that these spores can indeed attach themselves to the bottom of boots and waders, and become viable when reintroduced into clean water containing trout.”

Whirling disease is a neurological disorder caused by the parasite, Myxobolus cerebralis, which primarily affects juvenile trout causing severe deformities of the skeleton and skull – and can lead to mortality rates as high as 100 percent. It also can affect Atlantic salmon, steelhead and possibly other salmonids, though there have been fewer impacts on those species.

“Characteristically, it affects little fish – the fry – which then swim around in circles and, if the infection is severe enough, eventually most will die,” Reno said. “After the spores enter through the skin, the parasite eventually works its way through the fish and imbeds into their skulls and skeleton, degrading the cartilage. Originally, it was thought to affect the equilibrium of the fish, but a few years ago an anatomist found that the degraded cartilage was actually pinching their nerves and causing deformities.

“If the fish are big enough, they seem to be able to withstand the effects,” added Reno, who is a professor in OSU’s College of Agricultural Sciences. “That may explain why it hasn’t caused as many problems with salmon and steelhead.”

The disease was first recorded in U.S. waters in the mid-1950s in Pennsylvania, and it slowly made its way west, appearing in Colorado in the early 1980s, and in Montana’s blue-ribbon trout rivers in the mid-1990s.

In Oregon, whirling disease has been identified over the past two decades in tributaries of the Grande Ronde system in the northeastern part of the state, and more recently in Clear Creek on the Clackamas River system.

The life cycle of the parasite causing whirling disease is complex, Reno said. Once established in the skull of an adult fish, Myxobolus cerebralis, which is only about 10 microns, or .01 millimeters in size, is released into the water after the fish dies and decomposes. These microscopic parasites are then devoured by tubifex worms that live in the mud of freshwater streams and lakes, he added.

“These worms act as a second host for the parasite, which metamorphoses into these 300-micron monsters that are shaped like a river anchor,” Reno said. Then known as triactinomyxon, or “TAMs,” the parasites remain in the mud-dwelling worms until they are excreted into the lower water column. Nearby trout redds are particularly vulnerable to the parasite, which can attach to the skins and shoot spores into the juvenile trout, penetrating their skin and beginning the cycle once again.

Interestingly, the TAMs only live in certain strains of host tubifex worms.

“Susceptible strains of tubifex worms are found pretty widely across the state, as are strains that are more resistant,” said Jerri Bartholomew, a microbiologist with OSU’s Center for Fish Disease Research. “There is no obvious reason why whirling disease hasn’t become established in other places in Oregon, except that tubifex densities are often fairly low.”

In their studies, Reno and his colleagues at OSU’s Hatfield Marine Science Center in Newport wore waders and stepped into a water tank that contained mud with tubifex worms at the bottom. They found that stepping in the mud containing infected worms released the spores, which then attached to the waders. Wearing the waders into a separate clean tank, with healthy rainbow trout, was enough to infect the fish.

Conversely, when dead, infected trout were used as a source of the parasite, the spores adhering to the bottom of the waders could infect the worms. Even after the waders were left to dry for several hours, enough infectious material remained to infect new hosts.

Reno said the OSU researchers also tested whether the parasite could be passed through birds – especially mergansers, mallards and crows – that might feed on the juvenile fish or worms, but results were inconclusive.

Rainbow trout appear most susceptible to whirling disease, Reno said, and European researchers are developing strains of fish that are more resistant to infection.

The OSU study was funded by Montana State University.

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Paul Reno,
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DESPITE APPEARANCES, DON'T DISTURB THE BABY SEALS

NEWPORT - A newborn seal pup may look cute - even pathetic - but the fact that it's alone on the beach doesn't mean it's been abandoned, or that people should try to "rescue" it.

Spring is delivery time for thousands of expectant mother seals - and each year visitors to the Oregon coast report by the hundreds apparent strandings of seal pups.

But it's perfectly normal for mother seals to leave their offspring on the beach while they're off foraging for food, explained Bruce Mate, director of Oregon State University's endowed marine mammal program. The pups are too weak to swim long distances, and the mothers have uncanny instincts for relocating the spots where they left their young.

A well-intentioned person who tries to rescue such an "abandoned" pup by removing it from the beach or dragging it into the water may actually be sentencing the young animal to death.

When a seal pup is removed from the beach, it is almost impossible to reunite it with its mother, said Mate, who also is a marine mammal specialist for OSU's Extension Sea Grant program. The pups are difficult to feed and rarely survive in captivity, he added.

Approaching baby seals can also be dangerous to people, Mate said. Seal bites can be painful and may cause infection in people and pets. And people who disturb the pups, even with the best of intentions, risk being fined under laws which protect marine mammals from harassment.

Mate also urged visitors to keep their dogs on leashes when strolling along the beach. When dogs run free, he said, they can scare away mother seals trying to return to their pups.

Anyone who finds a baby seal which seems to be in obvious distress should stay away from the animal and report the sighting to the Oregon State Police, Mate said.

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Bruce Mate, 541-867-0236

OSU'S HILDERBRAND HONORED BY USDA

CORVALLIS - Kenneth Hilderbrand, an Oregon State University Extension seafood specialist, has been honored by the U.S. Department of Agriculture.

Hilderbrand, who works with OSU-based Oregon Sea Grant, was cited for his national leadership in educating and training seafood processors about new consumer safety rules.

Working out of OSU's Hatfield Marine Science Center in Newport, Hilderbrand was instrumental in forming the nationwide Seafood HACCP Alliance for Education and Training. The coalition of scientists, industry leaders and agency staff has been working to help processors implement the recently adopted federal Hazard Analysis and Critical Control Point (HACCP) system, which provides for a series of boat-to-market check points for product safety.

The USDA praised Hilderbrand "for outstanding contributions and national leadership" in the alliance's work to help processors "provide safe, wholesome aquatic food products to consumers worldwide."

While working with the alliance, Hilderbrand has helped design a manual and is planning workshops to teach seafood processors more about HACCP and other food-safety and quality assurance methods.

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Gary L. Jensen, USDA 202-401-5787

OSU Marine Science Center public wing to reopen Feb. 1

NEWPORT - After closing nearly two years ago for renovation, the public exhibit area of Oregon State University's Mark O. Hatfield Marine Science Center will reopen with limited, temporary displays on Saturday, Feb. 1.

Winter hours will be 10 a.m. to 4 p.m. daily. Admission is free, but donations will be accepted. The center is next to the Oregon Coast Aquarium.

Interim exhibits include a temporary touch tank, an erosion table, films, a crab research area, microscopic displays, and marine "biofact" stations, said Terri Nogler of the center's OSU Extension Sea Grant program.

"The bookstore will be open and we'll have oyster races," she added. The oyster "tracks" are tanks of oysters and plankton. "Since oysters don't run, the winner will be determined by which tank is cleared first of plankton." The center's new, permanent exhibits will begin to arrive the third week of February, she said. Tentative plans call for the renovation to be completed and a grand opening ceremony on May 17.

Age was the factor leading to the renovation, which started in 1995 with a $5 million grant from the National Aeronautics and Space Administration and the U.S. Department of Housing and Urban Development.

The OSU center's public wing first opened in 1965 with 10,000 square feet of exhibit space. The wing is being enlarged to 15,000 square feet and dated displays are gone to make way for exhibits that focus on the exhibition's theme, "Search for Patterns in a Complex World."

Plans for the permanent exhibit include a main gallery where visitors progress through four zones, each examining the marine world at different scales. The Global Scale zone features exhibits on marine mammals, the geology of ocean floor and the dynamics of the open ocean. The Bird's Eye area will compare dry land forests to the kelp forest of the ocean. Visitors will also learn about coastal hazards and what's happening on the beach.

There will be aquaria in each of the zones with animals and plants and interactive exhibits, including some computer games.

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Lavern Weber, 541-867-0211

OSU Marine Science Center grand opening set May 17

NEWPORT - After nearly two years, visitors will get a hands-on chance to enjoy the multi-million dollar remodeling of Oregon State University's Mark O. Hatfield Marine Science Center in Newport.

The center's public wing reopens at 10 a.m. Saturday, May 17. Winter hours, which continue through May 23, are 10 a.m. to 4 p.m. Thursday through Monday. From May 24 through Labor Day, hours are 10 a.m. to 6 p.m. daily. Admission is free, but donations will be accepted.

Grand opening ceremonies start at 2 p.m. May 17 with a keynote address by former Oregon Sen. Mark Hatfield. The official ceremonies will conclude with a flag ceremony by staff from the Coast Guard's Yaquina Bay Station.

While visitors will find more than 20 new exhibits, some favorites remain. The octopus touch tank endures, but was remodeled, enlarged and placed on the floor. The tidepool touch tank was also rebuilt.

New additions rely on high technology to quickly bring research from OSU scientists to the public. Attractions include a main gallery that progresses through four zones, each examining the marine world at different scales.

The Global Scale zone features exhibits on marine mammals, the geology of ocean floor and the dynamics of the open ocean. The Bird's Eye area will compare dryland forests to the kelp forest of the ocean. Visitors will also learn about coastal hazards and what's happening on the beach.

There will be aquaria in each of the zones with animals and plants and interactive exhibits, including some computer games.

Age was the factor leading to the renovation, which started in 1995 with a $5 million grant from the U.S. Department of Housing and Urban Development and the National Aeronautics and Space Administration.

The OSU center's public wing first opened in 1965 with 10,000 square feet of space. The wing now stands at 15,000 square feet.

Source: 

Lavern Weber, 541-867-0211

Douglas-fir and geoducks make strange bedfellows in studying climate change

NEWPORT, Ore. – Scientists are comparing annual growth rings of the Pacific Northwest’s largest bivalve and its most iconic tree for clues to how living organisms may have responded to changes in climate.

Analyzed by themselves, the rings from a single tree or mollusk may sometimes reflect conditions that are either favorable or unfavorable for growth. When scientists look at numerous individuals of the same species, however, the consistency of the ring patterns allows them to build a model and compare that to known climatic measurements.

But when you add in a second species – and compare the growth rings of geoducks and Douglas-firs, for example – the reliability of the data increases significantly, according to Bryan Black, a dendrochonologist at Oregon State University. Black has been applying tree-ring techniques to the growth increments of long-lived marine and freshwater species.

“When we associate rings from one species with known sea surface temperatures, we can account for almost 50 percent of the variability in the instrument records,” Black said. “But when we add the data from a second species, we can increase that number to 70 percent or more. And that’s important because it is allowing us to go back and create more accurate models of sea surface temperatures and at time scales more than twice the length of the instrument measurements.

“Each species brings its own ‘perspective’ of past climate, such that their combination provides a more accurate account,” Black added.

Results of the study are being published in the professional journal, Palaeogeography, Palaeoclimatology, Palaeoecology. Other authors include Carolyn Copenheaver of Virginia Tech, David Frank of the Swiss Federal Institute for Forest, Snow and Landscape Research, and Matthew Stuckey and Rose Kormanyos of OSU’s Hatfield Marine Science Center.

Sea surface temperatures are an important factor in analyzing the effects of climate change, said Black, a researcher at OSU’s Hatfield Marine Science Center in Newport and lead author on the study. Any methodology that improves scientists’ ability to estimate their past variability is met with interest in the research community. This new study has enabled scientists to develop an improved model of sea surface temperatures in the northeastern Pacific Ocean dating back to 1880.

When Black first began publishing comparisons of tree rings and the otoliths – or ear bones – of long-lived fish, he attracted the attention of climate change scientists.

“We found that chronologies for rockfish living at the 300-meter depth in the Pacific strongly related to tree-ring chronologies in the Cascade Mountains as well as to Pacific geoduck along the coast,” Black said.

That study, recently published by Black in the professional journal Marine Ecology-Progress Series, showed that climate synchronized the growth of organisms from the continental shelf to alpine forests.

“The next step was to use the longest-lived organisms – trees and the geoduck – to tell us about climate prior to the start of instrumental records,” Black pointed out.

Sea surface temperatures affect climate on land and when there is a spike in average yearly temperatures, such as during an El Nino year, it can have a profound impact on both trees and marine life. In general, Black said, warmer temperatures boost metabolism in geoduck and result in greater growth rates. Warm sea surface temperatures also mean less snow in the Cascade Mountains and a longer growing season for Douglas-firs and other trees, which are reflected in wider growth rings.

The limiting factor in using growth rings to study climate change is the age of the geoduck specimens. Old-growth evergreens may reach 500 to 1,000 years in age, but geoducks rarely exceed 150 years.

“Scientists at the Canadian Department of Fisheries and Oceans are dredging up shells of dead geoducks from the ocean floor,” Black said, “and we hope we can append their growth patterns to chronology developed from live individuals. If so, it may be possible to extend geoduck chronologies over several centuries and greatly extend our climate histories.”

Black is working with Jason Dunham, an ecologist with the U.S. Geological Survey in Corvallis, and OSU graduate student Brett Blundon to apply tree ring techniques to freshwater mussels, which also show annual growth through rings. They recently discovered that wider growth rings reflect low river flows during that year, which is another valuable piece of climate information.

“We’re not sure why low river flows are associated with good growth in freshwater mussels,” Black said. “High-flow events may damage the mussel, while low-flow events may be associated with higher food levels. But it is another example of how aquatic organisms can provide valuable information on climate impacts and history.”

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Bryan Black, 541-867-0283

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Pacific geoduck peel

This magnified slice of a geoduck shell clearly shows incremental growth rings used by scientists to analyze sea surface temperatures (Photo courtesy of Bryan Black, OSU)

Geoduck tree core

A core taken by Bryan Black from this large Douglas-fir near Cape Perpetua will be dated and its rings compared with those of other trees as well as geoducks – the Northwest’s largest bivalve. Such comparisons allow scientists to study climate change in new ways (photo courtesy of Bryan Black, OSU)

Figure showing a sea surface temperature

This figure shows reconstructed sea surface temperatures using growth ring analysis from geoducks and Douglas-fir trees. The accuracy allows scientists to extend the record of sea surface temperatures back to 1880 – far before the first instrument measurements (Graphic courtesy of Bryan Black, OSU)