Magnetic navigation may hold a key to salmon migration

Salmon - photo by Jeffrey BasingerAfter years at sea, sockeye salmon returning to their freshwater homes may be guided by an early memory of the Earth’s magnetic field, encoded at the site where natal streams empty into the Pacific Ocean, according to a an Oregon Sea Grant-supported study published today in Current Biology.

Oregon State University’s Nathan Putnam and David Noakes, along with researchers from the University of North Carolina Chapel Hill, the University of Washington, and the University of California Davis, pored over 56 years of dta from federal fishery scientists who tracked the movements of salmon at the mouth of British Columbia’s Fraser River, where fish must choose to swim north around Vancouver Island, or around to the south. They matched that data with  measurements of the Earth’s geomagnetic field, which shifts predictably in strength and orientation over time and found that fish tended to choose the path where the field strength was more similar to that of the river mouth when they’d left, two years before.

Scientists hope the finding will help solve the mystery of how salmon find their way back to the rivers of their birth across thousands of miles of ocean. It’s already accepted that in the final stages of the journey to their breeding grounds, salmon use odors to guide them back to the stream or inlet where they hatched. But how the fish find their target river remains a mystery, although scientists have suspected for a while that magnetic cues play a role. Last summer, a team including UNC-Chapel Hill researcher Kenneth Lohmann – also part of this study – reported that rotating magnetite crystals in a fish nose responded to magnetic field orientation, providing a possible biological mechanism for magnetic field tracking.

The OSU researchers hope to further investigate the magnetic field correlation by subjecting captive fish to artificial magnetic fields and studying their behavior.

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Rising stream temperatures could spell trouble for salmon

A newly published study by researchers at Oregon State University and two federal agencies concludes that high temperatures coupled with lower flows in many Northwest streams is creating increasingly extreme conditions that could spell trouble for salmon and other organisms.

The study, published in the professional journal Hydrobiologia, was funded and coordinated by the U.S. Geological Survey and the research branch of the U.S. Forest Service. It points to climate change as the primary cause.

“The highest temperatures for streams generally occur in August, while lowest flows take place in the early fall,” said Ivan Arismendi, a research professor in OSU’s Department of Fisheries and Wildlife. “Each period is important because it is a time of potentially high stress on the organisms that live in the stream. If they occur closer in time – or together – they could create double trouble that may be greater than their combined singular effects.”

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Newport’s Commercial Fisheries bay front signs now available online

Newport dock interpretive signsPeople who visit the bay fronts of Oregon’s harbors often see working boats at dock and wonder about them and about the types of commercial fishing being done along the coast. A series of 10 Newport’s Commercial Fisheries signs are now available to answer some of those questions. Not only can the bay front signs be viewed as you walk along the dock, they can also be found online:

Also available online is a free set of seven short publications explaining gear on fishing boats:


Netcasts – Jerri Bartholomew, Salmon Researcher, Glass Artist

At the intersection of science and art, you’ll find Jerri Bartholomew, a microbiologist and salmon researcher who also has a passion for working with glass.

“I see my artwork as being parallel to my scientific experimentation,” she says. “Science is often a very long process–it may take months, years, or even decades to find an answer to something, whereas art… you can get into the studio and experiment and come out with a product within hours, days, or weeks.”

But whatever the time scale, Bartholomew’s passion for scientific processes is evident as she shares her successes in solving some of the mysteries behind a growing threat to Pacific salmon, a parasite called Ceratomyxa shasta. Like many other parasites, C. shasta has a complex life cycle, requiring both vertebrate and invertebrate hosts to successfully reproduce.

In this installment of Netcasts, we visit the John L. Fryer Salmon Disease Laboratory, where Bartholomew and her team are using genetic tools to piece together a puzzle, searching for the right ways to target parasites while protecting salmon.  We’ll also get a glimpse at some of her artwork, including some more recent pieces in a set called “Pages From a Naturalist Notebook.”

Hatchery salmon threaten wild populations, scientists say

A newly published collection of more than 20 studies by leading university scientists and government fishery researchers in Alaska, British Columbia, Washington, Oregon, California, Russia and Japan provides mounting evidence that salmon raised in man-made hatcheries can harm wild salmon through competition for food and habitat.

“The genetic effects of mixing hatchery fish with wild populations have been well-documented,” says journal editor David Noakes* from Oregon State University. “But until now the ecological effects were largely hypothetical. Now we know the problems are real and warrant more attention from fisheries managers.”

The research volume, published in the May issue of Environmental Biology of Fishes, brings together 23 peer-reviewed, independent studies carried out across the entire range of Pacific salmon, including some of the first studies describing the impact of hatcheries on wild salmon populations in Japan and Russia.

The studies provide new evidence that fast-growing hatchery fish compete with wild fish for food and habitat in the ocean as well as in the rivers where they return to spawn. The research also raises questions about whether the ocean can supply enough food to support future increases in hatchery fish while still sustaining the productivity of wild salmon.

“This isn’t just an isolated issue,” says Pete Rand, a biologist at the Wild Salmon Center and a guest editor of the publication. “What we’re seeing here in example after example is growing scientific evidence that hatchery fish can actually edge out wild populations.”

Losing wild fish would mean losing the genetic diversity that has allowed salmon to survive for centuries. Unlike hatchery fish, wild salmon populations have a range of highly specialized adaptations to the natural environment. These adaptations not only help them return to their home streams to spawn, but also increase their ability to withstand environmental changes like increases in ocean temperature and extreme variations in stream flows. Hatchery fish, as the name implies, are hatched from eggs fertilized in a controlled environment and raised in captivity until they are big enough to release into the natural environment. They lack the genetic diversity of wild fish that provides insurance against fisheries collapses.

* David Noakes is receiving Oregon Sea Grant support for current research into geomagnetic imprinting and homing in salmon and steelhead

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OPB highlights Sea Grant researcher

Oregon Sea Grant’s Guillermo Giannico and his study of the role flooded farmlands can play in fish survival are the subject of a new episode of Oregon Field Guide, broadcast on on Oregon Public Television this week.

Giannico, a fisheries ecologist with OSU’s Department of Fisheries & Wildlife who also serves as Sea Grant Extension fisheries specialist, was part of a team that set out a few years ago to learn whether dry-all-summer ditches that criss-cross Willamette Valley agricultural lands might house fish during the wet winter months.

What they found surprised them – and some of the farmers, too: A thriving winter habitat for several species of native fish.

Watch the Oregon Field Guide video, Ditch Fish:

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Documentary follows Sea Grant-supported research into salmon disease

Jerri Bartholomew with juvenile salmonKLAMATH FALLS – A new documentary, airing Feb. 7 on Southern Oregon Public Television, looks at the work of an Oregon Sea Grant-funded research effort to understand more about a lethal parasite that can infect wild salmon in the Klamath River and elsewhere in the Northwest.

Dr. Jerri Bartholomew, a microbiologist and director of Oregon State University’s salmon disease laboratory, has been studying Ceratomyxa shasta since she was an undergraduate. The parasite is a major cause of mortatlity in juvenile salmon, and may infect up to 80 percent of outmigrating juveniles in the Klamath River.  Bartholomew’s work – much of it funded by Sea Grant –  has led to new understanding of the parasite’s unusual life cycle, and how changes in water temperature and other environmental factors can cause it to proliferate.

The documentary, Saving Salmon, was scripted, directed and produced by Judith Jensen, director of Educational Solutions, a Klamath Falls nonprofit. Sea Grant videographer Steve Roberts contributed footage to the project, which is scheduled to air at 9 pm Feb. 7 on SOPTV.

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Oregon floods: fish should fare better than people

Calapooia River flooding near Albany, Jan. 20, 2012Heavy rain and melting snowpack that flooded Western Oregon last week turned creeks and rivers into broad, brown torrents that might look like bad news for fish. But an Oregon Sea Grant fisheries specialist says his research suggests the opposite.

Guillermo Giannico, a research professor in Oregon State University’s Department of Fisheries and Wildlife, has conducted studies showing that fish – especially native species – can find refuge and food in flooded grass-seed fields.

Giannico’s research grew out of a project by fellow OSU researcher Stan Gregory to map the historic path of the Willamette River. The Willamette and its many tributaries once were more complex, braided streams. Multiple channels dispersed the impact of flooding, but dams, housing developments and forest transition have since funneled many rivers into single channels that run fast and furious during floods.

Giannico and others wondered how fish adapted to the change. Floods have happened for thousands of years, he said, and fish traditionally escaped high water in the main river stems by moving to off-channel habitat.

Turns out they still do. During seasonal floods, researchers took a look at ditches, low-lying farmland and other spots that are above water most of the year. To their surprise, they found 14 fish species — 11 of them native.

“That’s high diversity for this area, more than I would have bet we were going to get,” Giannico said.

Giannico noted a couple implications from the findings. Salmon, steelhead and other native fish, he said, are keenly tuned to changes in light and water temperature, and move to sheltering habitat — even if it turns out to be a flooded grass seed field. Invasive fish, often warm-water species, don’t get it. They’re unable to respond to the clues. As a result, native fish get a temporary break from predation and competition for food.

“Floods have always been a dynamic part of the system, much the same way that snow is for elk in Yellowstone,” said Giannico  “Over time, animals will adapt to get the most out of their habitat. We have found that native fish have adjusted their behavior to use these floodplains, mostly in agricultural lands, to great benefit.”

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Oregon Sea Grant publishes book about sustaining salmon ecosystems

The following publication may be purchased from Oregon Sea Grant.

Pathways to Resilience: Sustaining Salmon Ecosystems in a Changing World.

“Resilience holds the key to our future. It is a deceptively simple idea, but its application has proven elusive.”
—Jane Lubchenco, administrator of NOAA

Fishery management programs designed to control Pacific salmon for optimum production have failed to prevent widespread fish population decline and have caused greater uncertainty for salmon, their ecosystems, and the people who depend upon them. Strengthening salmon resilience will require expanding habitat opportunities for salmon populations to express their maximum life-history variation. Such actions also may benefit  human communities by expanding the opportunities for people to express diverse social and economic values.

The 11 essays in this book represent the most-forward thinking about resilience and Pacific salmon collected to date, and they point to new ways we may consider and interact with this iconic fish. It should be of interest not only to those active in fisheries but also to policymakers—and, by extension, to those interested in the resilience of other ecological and social systems.

By linking theory with practice, the authors of this volume have made a quantum leap forward in understanding how to manage critical populations. A must read for resilience scholars and practitioners.
—Lance Gunderson, Professor of Environmental Studies, Emory University

All too often, our attempts at conservation fail because we think too small. We fail to see connections, the broader context, and longer-term processes. The authors of this volume think big. Pathways to Resilience is just what we need for animals that migrate thousands of miles and cross ecosystem and political boundaries at will. This is worth reading and taking good notes.
—Jack E. Williams, Senior Scientist, Trout Unlimited

New on DVD! Cascade Head / Scenic Research Area

Cascade HeadGrab your hiking boots and binoculars! This video will take you on a scenic and historical walk through the beautiful prairie headlands, forests, and grassy marshes of Cascade Head and the adjoining Salmon River estuary.

Ever heard of Pixieland? Kami Ellingson, from the Siuslaw National Forest, will take us on a guided tour of the complex history of commercial and residential developments that once threatened to pave paradise.

Stay on the trails, because that little blue violet up on the headlands feeds the Oregon silverspot caterpillar, one of four threatened or endangered animal species that live here. The Nature Conservancy’s Debbie Pickering tells us the butterfly’s story.

Back in the marshes, NOAA Fisheries scientist Dan Bottom describes the history of a massive habitat-restoration project, in which dikes were removed from the estuary in the hope of improving salmon runs. Western Oregon University Professor Karen Haberman shares her Sea-Grant sponsored research in the marsh–an unusual focus area with surprising consequences.

And finally, Eric Vines gives us a tour of the Sitka Center for Art and Ecology, one of the many recreational opportunities at Cascade Head.

The full program is available on DVD from the Oregon State University Marketplace

Exclusive: Watch a short featurette not included on this DVD: Salmon River Marsh / Undergraduate Field Experiences (about 2 mins)