Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reconstructing Salmon Populations

05.12.2002


Management of Pacific Salmon has been an issue for years. To determine whether management goals are working, knowledge of historical populations can prove quite useful. In a recent study published in Ecology, Deanne C. Drake, Robert J. Naiman, and James M. Helfield, all of the University of Washington, paired annual tree ring growth with catch data to determine what salmon stocks looked like 200 years ago.



Born in freshwater lakes and rivers, salmon swim to the ocean where they feed and mature. After a few years, they return to the river or lake of their birth to reproduce and die. As their bodies decay, they leave behind ocean nutrients in the freshwater ecosystems.

"There is a great need to understand how many salmon returned to rivers historically," said Naiman. "Once we knew nutrients from salmon carcasses affected tree growth in certain species, it seemed possible to use tree rings to estimate how many salmon returned to a river in any one year. This was a ’trial’ project to see if the idea would work."


Previous studies determined the 300-year history of sockeye salmon in the ocean and lakes around Alaska by analyzing nitrogen isotopes in lake sediment records. This method is impossible to use for river habitats, where sediment is constantly washed downstream and out into the ocean.

The researchers examined both cool, dry boreal forests and warm, moist Pacific Northwest rainforests. Drake and Naiman could not find evidence in the tree rings of a relationship between the pacific climate pattern and salmon populations or determine historical salmon populations in the boreal forests. Yet in the rainforests, where they originally did not expect to find a strong correlation, the scientists noticed a pattern in the tree rings which corresponded with the records of salmon abundance along the river’s edge.

Using this information, the scientists set to reconstruct salmon numbers as far back as 1820. They verified their information by comparing records of commercial salmon catch numbers with the tree core samples, and then filled in the gaps for the missing human records of salmon populations.
"These reconstructions follow the general ups and downs of historical catch records, but we need to better understand the relationship between tree-ring growth and salmon before we can say this method is accurate." said Drake.

Another method which Naiman and others are currently looking into involves the measurement of nitrogen in tree rings. As the salmon decay, a particular type of nitrogen can be detected in soils and leaves near streams. These nitrogen isotopes have been measured in previous studies and found to relate to the massive deaths following spawning salmon.

According to Naiman, "Measuring nitrogen isotopes in tree rings is potentially more accurate, although much harder to determine."


Ecology is a peer-reviewed journal published twelve times a year by the Ecological Society of America (ESA). Copies of the above article are available free of charge to the press through the Society’s Public Affairs Office. Members of the press may also obtain copies of ESA’s entire family of publications, which includes Ecology, Ecological Applications, and Ecological Monographs. Others interested in copies of articles should contact the Reprint Department at the address in the masthead.

Founded in 1915, the Ecological Society of America (ESA) is a scientific, non-profit, organization with over 7800 members. Through ESA reports, journals, membership research, and expert testimony to Congress, ESA seeks to promote the responsible application of ecological data and principles to the solution of environmental problems. For more information about the Society and its activities, access ESA’s web site at: http://www.esa.org.

Annie Drinkard | esa
Further information:
http://www.esa.org

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>