Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study links ecosystem changes in temperate lakes to climate warming

18.12.2008
Unparalleled warming over the last few decades has triggered widespread ecosystem changes in many temperate North American and Western European lakes, say researchers at Queen's University and the Ontario Ministry of the Environment.

The team reports that striking changes are now occurring in many temperate lakes similar to those previously observed in the rapidly warming Arctic, although typically many decades later. The Arctic has long been considered a "bellwether" of what will eventually happen with warmer conditions farther south.

"Our findings suggest that ecologically important changes are already under way in temperate lakes," says Queen's Biology research scientist, Dr. Kathleen Ruhland, from the university's Paleoecological Environmental Assessment and Research Lab (PEARL) and lead author of the study.

The research was recently published in the international journal Global Change Biology. Also on the team are Biology professor John Smol, Canada Research Chair in Environmental Change, and Andrew Paterson, a research scientist at the Ontario Ministry of the Environment and an adjunct professor at Queen's.

One of the biggest challenges with environmental studies is the lack of long-term monitoring data, Dr. Ruhland notes. "We have almost no data on how lakes have responded to climate change over the last few decades, and certainly no data on longer term time scales," she says. "However, lake sediments archive an important record of past ecosystem changes by the fossils preserved in mud profiles."

The scientists studied changes over the last few decades in the species composition of small, microscopic algae preserved in sediments from more than 200 lake systems in the northern hemisphere. These algae dominate the plankton that float at or near the surface of lakes, and serve as food for other larger organisms.

Striking ecosystem changes were recorded from a large suite of lakes from Arctic, alpine and temperate ecozones in North America and western Europe. Aquatic ecosystem changes across the circumpolar Arctic were found to occur in the late-19th and early 20th centuries. These were similar to shifts in algal communities, indicating decreased ice cover and related changes, over the last few decades in the temperate lakes.

"As expected, these changes occurred earlier – by about 100 years – in highly sensitive Arctic lakes, compared with temperate regions," says Dr. Smol, recipient of the 2004 Herzberg Gold Medal as Canada's top scientist.

In a detailed study from Whitefish Bay, Lake of the Woods, located in northwestern Ontario, strong relationships were found between changes in the lake algae and long-term changes in air temperature and ice-out records. The authors believe that, although the study was focused on algae preserved in lake sediments, changes to other parts of the aquatic ecosystem are also likely (for example algal blooms and deep-water oxygen levels).

"The widespread occurrence of these trends is particularly troubling as they suggest that climatically-induced ecological thresholds have already been crossed, even with temperature increases that are below projected future warming scenarios for these regions," adds Dr. Paterson. The authors warn that if the rate and magnitude of temperature increases continue, it is likely that new ecological thresholds will be surpassed, many of which may be unexpected.

"We are entering unchartered territory, the effects of which can cascade throughout the entire ecosystem," concludes Dr. Smol.

Nancy Dorrance | EurekAlert!
Further information:
http://www.queensu.ca

More articles from Ecology, The Environment and Conservation:

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>