Umeå University's logo

umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Climate change impacts on production and dynamics of fish populations
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Byström Karlsson ; EcoChange)
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Ongoing climate change is predicted to increase water temperatures and export of terrestrial dissolved matter (TDOM) to aquatic ecosystems influencing ecosystem productivity, food web dynamics and production of top consumers. Ecosystem productivity is mainly determined by the rates of primary production (GPP) in turn controlled by nutrients, light availability and temperature, while temperature alone affect vital rates like consumption and metabolic rates and maintenance requirements of consumers. Increased level of TDOM causes brownification of water which may cause light limitation in algae and decrease GPP and especially so in the benthic habitat. Temperature increase has a been suggested to increase metabolic rates of consumers to larger extent than the corresponding effect on GPP, which suggest reduced top consumer biomass and production with warming.

The aim of this thesis was to experimentally study the effects of increased temperature and TDOM on habitat specific and whole ecosystem GPP and fish densities and production. In a replicated large-scale pond experiment encompassing natural food webs of lotic ecosystems I studied population level responses to warming and brownification in the three- spined stickleback (Gasterosteus aculeatus).

Results showed overall that warming had no effect on whole ecosystem GPP, likely due to nutrient limitation, while TDOM input decreased benthic GPP but stimulated pelagic GPP. In fish, results first of all suggested that recruitment in sticklebacks over summer was negatively affected by warming as maintenance requirements in relation to GPP increased and thereby increased starvation mortality of young-of-the-year (YOY) sticklebacks. Secondly, brownification increased mortality over winter in YOY as the negative effect on light conditions likely decreased search efficiency and caused lower consumption rates and starvation over winter in sticklebacks. Third, seasonal production of YOY, older, and total stickleback production was negatively affected by warming, while increased TDOM caused decreased YOY and total fish production. The combined effect of the two was intermediate but still negative. Temperature effects on fish production were likely a result of increased energy requirements of fish in relation to resource production and intake rates whereas the negative effect of TDOM likely was a result of decreased benthic resource production. Finally, effects of warming over a three-year period caused total fish density and biomass and abundance of both mature and old fish to decrease, while proportion of young fish increased. The main cause behind the strong negative effects of warming on fish population biomass and changes in population demographic parameters were likely the temperature driven increased energy requirements relative to resource production and cohort competition.

The results from this thesis suggest that predicted climate change impacts on lentic aquatic ecosystems will decrease future densities and biomass of fish and negatively affect fish production and especially so in systems dominated by benthic resource production.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 2016. , p. 30
Keywords [en]
Temperature, terrestrial dissolved organic carbon, light extinction, GPP, recruitment, winter mortality, metabolism, cohort competition, fish production, fish biomass
National Category
Ecology
Identifiers
URN: urn:nbn:se:umu:diva-128007ISBN: 978-91-7601-604-6 (print)OAI: oai:DiVA.org:umu-128007DiVA, id: diva2:1048637
Public defence
2016-12-16, Lilla hörsalen, Linnaeus väg, Umeå, 10:00 (English)
Opponent
Supervisors
Available from: 2016-11-25 Created: 2016-11-21 Last updated: 2018-06-09Bibliographically approved
List of papers
1. Warming but not increased terrestrial doc has negative effects on fish recruitment
Open this publication in new window or tab >>Warming but not increased terrestrial doc has negative effects on fish recruitment
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Water temperature and export of terrestrial dissolved organic carbon (DOC) to recipient aquatic ecosystems have strong impacts on ecosystem productivity. Increased DOC concentration causing brownification of water is argued to reduce fish production by decreasing light availability for autotrophic production. On the other hand, higher temperatures have been shown to correlate positively with fish recruitment. This increase has been related to increased growth rates and survival of young-of-the-year (YOY) fish with warming. However, whether or not increased temperature results in higher growth depends on resource availability, suggesting a relationship between individual gain and recruitment mediated via the interplay between resource production and temperature. In a replicated, large scale experimental pond ecosystem, we tested the effects of increased temperature (+3oC) and terrestrial DOC concentrations (+4 mg/l) on recruitment (size, density and biomass) of three-spined sticklebacks over one growth season. Gross primary production (GPP) was similar between treatments, whereas zooplankton and benthic invertebrate biomass were negatively affected by increased temperature and if any higher at increased DOC levels. Increased temperature had no effect on individual size but negative effects on body condition and recruitment of YOY sticklebacks, while increased DOC concentration had no effect on recruitment. No positive effect of temperature increase on GPP and decreased resource levels in combination with higher metabolic costs, are suggested to increase starvation mortality and to be the main mechanism behind observed negative effects of warming on recruitment. Based on our results, we suggest that climate change may, counter intuitively, have negative effects on fish recruitment due to decreased carrying capacity of nursery habitats as a consequence of increased energy requirements in juvenile fish in relation to the net effects on resource production and ecosystem productivity. 

Keywords
Temperature, metabolism, search efficiency, dissolved organic carbon (DOC), Gross primary production (GPP), somatic growth, macroinvertebrates
National Category
Ecology
Identifiers
urn:nbn:se:umu:diva-127938 (URN)
Funder
The Kempe FoundationsSwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2011-3908Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGE
Available from: 2016-11-21 Created: 2016-11-21 Last updated: 2018-06-09
2. Brownification increases winter mortality in fish
Open this publication in new window or tab >>Brownification increases winter mortality in fish
Show others...
2017 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 183, no 2, p. 587-595Article in journal (Refereed) Published
Abstract [en]

In northernclimateswinter is a bottleneck for many organisms. Low light and resource availability constrain individual foraging rates,potentially leading tostarvation and increasedmortality.Increasinginput of humic substances to aquatic ecosystems causesbrownification of water and hence a further decreaseof light availability,which may lead tofurther decreased foraging ratesand starvation mortality during winter.To test this hypothesis, we measured the effectsof experimentally increased humicwaterinput on consumption and survival of young-of-the-year (YOY) three-spined stickleback (Gasterosteus aculeatus) over winterin largeoutdoor enclosures. Population densitieswereestimated in autumn andthefollowing springand food availabilityand consumptionwere monitoredoverwinter. As hypothesized,mortality washigher underhumic(76%)as compared to ambientconditions (64%).Also, body condition and ingested prey biomass werelower under humic conditionseven thoughresource availability wasnotlower under humic conditions. Light conditions were significantly poorer under humic conditions. This suggeststhat increased mortality and decreased body condition and ingested prey biomasswasnot due to decreased resource availability but due todecreasedsearch efficiencyin this visual feeding consumer. Increased future brownification of aquatic systems may therefore negatively affect both recruitment and densities of fish.

Keywords
Brownification, winter mortality, light limitation, feeding efficiency, metabolism
National Category
Ecology
Identifiers
urn:nbn:se:umu:diva-127940 (URN)10.1007/s00442-016-3779-y (DOI)000394254500023 ()2-s2.0-85001099564 (Scopus ID)
Funder
The Kempe FoundationsSwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2011-3908Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGE
Note

Originally published in manuscript form.

Available from: 2016-11-21 Created: 2016-11-21 Last updated: 2023-03-24Bibliographically approved
3. Population and size dependent responses in fish production to climate change
Open this publication in new window or tab >>Population and size dependent responses in fish production to climate change
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Climate change is predicted to increase water temperatures and export of terrestrial dissolved matter (TDOM) to aquatic ecosystems with concomitant effects on ecosystem productivity and production of consumers at the top of the food web. Here we study how increased level of TDOM and temperature alone or in combination affect benthic and pelagic primary production and biomass production of fish in replicated large scale outdoor pond experiment. We increased temperature (+3 ̊C) and TDOM concentrations (×2.5) using natural high TDOM water from a small creek and used naturally reproducing three-spine sticklebacks (Gasterosteus aculeatus) populations as model fish species. Gross primary production (GPP) was similar to ambient control conditions in all treatments although increased TDOM concentrations deceased benthic but stimulated pelagic GPP, presumably as a result of decreased light availability and increased nutrient availability, respectively. The production of young-of-the-year (YOY), older, and total fish population were negatively affected by warming, whereas increased TDOM caused decreased YOY and total fish production. Effect of temperature on fish production were likely a result of increased metabolic cost in relation to resource production and intake rates whereas the negative effect of TDOM on fish production was likely a result of decreasing benthic resource production. However, the combined effect on fish production of warming and TDOM was only intermediate compared to individual treatments. Our study suggest climate change will lead to decreased fish production and that the effect may be most pronounced in clear systems dominated by benthic GPP . 

National Category
Ecology
Research subject
Animal Ecology
Identifiers
urn:nbn:se:umu:diva-127935 (URN)
Funder
The Kempe FoundationsSwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2011-3908Ecosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGE
Available from: 2016-11-21 Created: 2016-11-21 Last updated: 2018-06-09
4. Warming decrease fish population densities and biomass
Open this publication in new window or tab >>Warming decrease fish population densities and biomass
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Temperature impact all biota and ecosystems through its direct effect on the vital rates of primary producers and consumers. Still, how these changes in rates translates through ecosystem feed backs to the population level of top consumers are poorly understood. Here, we studied effects of temperature increase (+ 3 ̊C during ice free season) on fish population dynamics in a replicated large scale pond ecosystem experiment over 3 years. Increased temperature had no significant effect on whole ecosystem gross primary production while top down effects of warming on intermediate consumers changed from negative to positive due to negative effects of warming on fish population abundance. Total fish density and biomass and abundance of both mature and old fish decreased with warming, while proportion of young fish increased, with warming. The effects of warming on fish population demographics were likely due to that temperature increased cohort competition and fish energy requirements relative to resource production. Our results suggest that global warming may increase competition, favor young individuals and overall decrease fish population densities and biomass. 

National Category
Ecology
Identifiers
urn:nbn:se:umu:diva-127936 (URN)
Available from: 2016-11-21 Created: 2016-11-21 Last updated: 2018-06-09

Open Access in DiVA

spikblad(83 kB)85 downloads
File information
File name SPIKBLAD01.pdfFile size 83 kBChecksum SHA-512
08c6383ee2474be29d694de73abc8f5c60fd79cab56dfd333938443bb294e1a7df56e80cd6d85e4f2913549b17cec597b4f72aca40a212342ce922cf952cace4
Type spikbladMimetype application/pdf
fulltext(9736 kB)408 downloads
File information
File name FULLTEXT02.pdfFile size 9736 kBChecksum SHA-512
81062464713003c29aacc77be3530199d2a30cc13bfe9da9cde478caadcacb28940d2810a5b5322634d65f3bd5d6c103caaf9337f53bff5efdba4a5f134deb33
Type fulltextMimetype application/pdf

Authority records

Hedström, Per

Search in DiVA

By author/editor
Hedström, Per
By organisation
Department of Ecology and Environmental Sciences
Ecology

Search outside of DiVA

GoogleGoogle Scholar
Total: 449 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1948 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf