Jan Karlsson

Greenhouse emissions from Siberian rivers peak as permafrost thaws

Greenhouse emissions from Siberian rivers peak as permafrost thaws

Permafrost soils store large quantities of frozen carbon and play an important role in regulating Earth’s climate. In a study published in Nature Geoscience, researchers from Umeå University, Sweden, in collaboration with an international team, now show that river greenhouse gas emissions rise high in areas where Siberian permafrost is actively thawing.

Good news for fishermen: “Browning” impacts fish less than expected

Water color is getting darker in lakes across the planet. This phenomenon, known as “browning,” was anticipated to cause widespread declines in fish populations. A new study by researchers from Umeå University finds that the number of fish populations impacted by browning is smaller than previously believed.

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Original article:
David Seekell, Pär Byström, and Jan Karlsson, Lake morphometry moderates the relationship between water color and fish biomass in small boreal lakes. Limnology and Oceanography. 2018. doi: 10.1002/lno.10931

For more information, please contact:

David Seekell, Assistant professor, Department of Ecology and Environmental Science, Umeå University, Sweden

Limnology and Oceanography Research Exchange (LOREX)

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Limnology and Oceanography Research Exchange (LOREX) is an NSF funded initiative to provide training in international research for graduate students. Graduate student research is often constrained by the resources, ideas, and culture of the home institution. International collaborations enhance graduate students’ ability to think critically and creatively, make cross-disciplinary connections, and stretch one's field of view while gaining competency in an international environment and increasing their network of colleagues.

Opportunities for research exchanges in freshwater ecology, aquatic biogeochemistry and paleolimnology are possible with CIRC at Umeå University.

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New Paper: Lake morphometry moderates the relationship between water color and fish biomass in small boreal lakes

Globally, lake waters are thought to be getting darker due to increasing concentrations of dissolved organic carbon - an amalgam of thousands of uncharacterized carbon compounds that get flushed into lakes from surrounding areas. It's been predicted that this change in water color will lead to declining fish populations, but prior studies haven't considered how variations in lake depth might affect this relationship.

Seekell, D. A., P. A. Byströn, & J. Karlsson 2018. Lake morphometry moderates the relationship between water color and fish biomass in small boreal lakes. Limnology and Oceanography. Early Online. DOI: 10.1002/lno.10931

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Aktum - På vandring över fjället mot framtidens klimat

I den känsliga fjällmiljön kan man se klimatförändringarna med blotta ögat. Till forskningsstationen i Abisko kommer därför forskare från hela världen. En av verksamheterna som bedriver klimatstudier i den svenska fjällen är Climate Impacts Research Centre, CIRC, vid Umeå universitet. 

Mountain fish threatened by warmer climate

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Climate research funded by the Knut and Alice Wallenberg Foundation

Warmer and browner water, lower oxygen levels, and a decline in food availability hit game fish hard. And greenhouse gas emissions are rising. Researchers in Umeå are trying to create a model to predict the rate at which a warming climate will impact lakes in the north.

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Phys.org: It's a fish eat tree world: Study finds widespread support that lakes are fed by their watersheds

Phys.org: It's a fish eat tree world: Study finds widespread support that lakes are fed by their watersheds

Most of the planet's freshwater stores are found in the northern hemisphere, a region that is changing rapidly in response to human activity and shifting climatic trends. An international team of scientists analyzed 147 northern lakes and found that many rely on nutrients from tree leaves, pine needles, and other land-grown plants to feed aquatic life.