Warmer and browner waters decrease fish biomass production

Renee M. Van Dorst*, Anna Gårdmark, Richard Svanbäck, Ulrika Beier, Gesa A. Weyhenmeyer, Magnus Huss

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)

Abstract

Climate change studies have long focused on effects of increasing temperatures,
often without considering other simultaneously occurring environmental changes, such as browning of waters. Resolving how the combination of warming and browning of aquatic ecosystems affects fish biomass production is essential for future ecosystem functioning, fisheries, and food security. In this study, we analyzed individual‐ and population‐level fish data from 52 temperate and boreal lakes in Northern Europe, covering large gradients in water temperature and color (absorbance, 420 nm). We show that fish (Eurasian perch, Perca fluviatilis) biomass production decreased with both high water temperatures and brown water color, being lowest in warm and brown lakes. However, while both high temperature and brown water decreased fish biomass production, the mechanisms behind the decrease differed: temperature affected the fish biomass production mainly through a decrease in population standing stock biomass, and through shifts in size‐ and age‐distributions toward a higher proportion of young and small individuals in warm lakes; brown water color, on the other hand, mainly influenced fish biomass production through negative effects on individual body growth and length‐at‐ age. In addition to these
findings, we observed that the effects of temperature and brown water color on
individual‐level processes varied over ontogeny. Body growth only responded positively to higher temperatures among young perch, and brown water color had a stronger negative effect on body growth of old than on young individuals. Thus, to better understand and predict future fish biomass production, it is necessary to integrate both individual‐ and population‐level responses and to acknowledge within species variation. Our results suggest that global climate change, leading to browner and warmer waters, may negatively affect fish biomass production, and this effect may be stronger than caused by increased temperature or water color alone
Original languageEnglish
Pages (from-to)1395-1408
JournalGlobal Change Biology
Volume25
Issue number4
Early online date20 Dec 2018
DOIs
Publication statusPublished - Apr 2019

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Keywords

  • biomass production
  • browning
  • Climate change
  • Eurasian perch
  • fish
  • individual body grwoth
  • lakes
  • length distribution
  • ontogeny
  • warming

Cite this

Van Dorst, R. M., Gårdmark, A., Svanbäck, R., Beier, U., Weyhenmeyer, G. A., & Huss, M. (2019). Warmer and browner waters decrease fish biomass production. Global Change Biology, 25(4), 1395-1408. https://doi.org/10.1111/gcb.14551