Climate Change Effects on Fishes

by

Ivan Nagelkerken, Bridie Allan, David Booth, Jennifer Donelson, Camille Mellin, Timothy Ravasi, Jodie Rummer

• LAST REVIEWED: 20 February 2024
• LAST MODIFIED: 20 February 2024
• DOI: 10.1093/obo/9780199830060-0252

Introduction

Fishes comprise the most diverse group of aquatic vertebrates and are found across the world’s aquatic biomes and ecosystems — in freshwater, estuaries, as well as in the ocean. With this diversity also comes an extensive array of life histories, behaviors, physiologies, and adaptations. In addition to long-term direct human perturbations on fish populations and communities, such as overfishing, habitat destruction, and aquatic pollution, indirect human stressors such as various climate change stressors are now increasingly having an impact on many fish species as well. It is predicted that climate change stressors such as warming, acidification, and hypoxia will alter fish biodiversity, change their geographic distributions, alter their fitness and performance, and create novel community structures. Due to their rich diversity, it is difficult to predict how each fish species will respond to the interplay of various climate stressors. However, fish species can often be classified into guilds, functional groups, life history strategies, etc., based on various traits. As such, some generalizable patterns may emerge on how specific (taxonomic/functional) groups of fish species might respond to current and future climate change. This bibliography covers key studies on climate change effects on (predominantly marine) fishes, through the lens of fish ecology. It assesses the current published literature in terms of various research fields in fish ecology, scaling up from cellular, individual, and population levels to higher levels of biological organization such as communities, ecosystems, and biogeographies. Such a broad bibliography might provide for a better appreciation of the complexity of studying climate change impacts on fishes, as their ecology is intertwined with that of many other species, habitats, and environmental drivers. The ecological responses of fishes at multiple levels of biological organization mediate their fitness, performance, and persistence, and generalizable insights are needed for their biodiversity conservation, and to evaluate their importance for various ecosystem services, including fisheries.

General Overviews

Because the field of fish ecology is so broad, an extensive number of reviews exists on how various subfields of fish ecology are affected by climate change stressors. These reviews are dominated by the impacts of ocean warming and acidification, with much less published on, for example, the effect of hypoxia. In terms of ecosystems, coral reef fishes often dominate the literature, with much less known of fishes from estuarine and polar systems. Climate change effects on fish behavior and physiology have received much attention (and some controversy), with less emphasis on species interactions (although this field is on the rise). Studies on fish climate ecology in more natural environments (e.g., global-warming hot spots, volcanic CO₂ vents, semi-enclosed bays, and upwelling areas) where natural complexity is present at its fullest are still scarce but gaining attention. This section highlights reviews across various subfields of fish ecology. Heuer and Grosell 2014, cited under Behavior, provides an extensive review on the effects of elevated anthropogenic CO₂ on various physiological systems and processes, as well as on sensory systems and behavior. Pörtner and Peck 2010 reviews the effects of ocean acidification, warming, and oxygen reduction on fish physiology, and additionally evaluates how physiological changes might affect fishes at various levels of biological organization. Comte and Olden 2017 provides a global analysis comparing the thermal sensitivities of freshwater versus marine fishes. Sampaio, et al. 2021 uses a meta-analysis to specifically study the impacts of hypoxia (versus warming and acidification) on the ecology of marine species, including fishes. Another meta-analysis on fish responses to ocean acidification is provided by Cattano, et al. 2018, while Wang, et al. 2020, cited under Life Histories and Ecological Niches, is a large-scale analysis of the effects of warming on the ecology of fishes, with emphasis on life history effects. Besides understanding the direct effects of climate stressors on fishes, it is also critical to understand how fishes may avoid or adjust to climate change. Crozier and Hutchings 2014 reviews phenotypic plasticity of various ecological traits as well as genetic adaptation in fishes in response to climate change, while Vergés, et al. 2014 describes how fishes that avoid climate change by extending their ranges to cooler environment are ecologically altering recipient ecosystems. Duffy, et al. 2016 is a global analysis testing how various human and climate stressors and biodiversity might affect fish biomass. Changes in fish productivity have consequences for fisheries. Nyboer, et al. 2021 is a global vulnerability assessment of marine and freshwater fishes to climate change, linking this to socioeconomic values and conservation efforts.

• Cattano, C., J. Claudet, P. Domenici, and M. Milazzo. 2018. Living in a high CO₂ world: A global meta-analysis shows multiple trait-mediated fish responses to ocean acidification. Ecological Monographs 88.3: 320–335.

  DOI: 10.1002/ecm.1297

  Meta-analysis on how ocean acidification affects multiple physiological and behavioral traits in marine fishes. Finds alterations (both negative and positive effects) in calcification, metabolism, yolk, behavior, predation risk, and foraging, but such changes were largely limited to more extreme pCO₂ elevations (300–750 μatm). Notes that climate change effects on reproduction, development, and habitat choice of fishes are still understudied.

• Comte, L., and J. D. Olden. 2017. Climatic vulnerability of the world’s freshwater and marine fishes. Nature Climate Change 7.10: 718–722.

  DOI: 10.1038/nclimate3382

  Studies the thermal tolerances of 2,960 freshwater and marine fish species. Finds that for marine systems, fishes in the tropics are most at risk, while for freshwater systems, fishes from higher northern latitudes appear most sensitive. These stark differences between biomes are stipulated to be the consequence of their different biogeographical histories.

• Crozier, L. G., and J. A. Hutchings. 2014. Plastic and evolutionary responses to climate change in fish. Evolutionary Applications 7.1: 68–87.

  DOI: 10.1111/eva.12135

  Evaluates the degree of phenotypic responses in marine and freshwater fishes to climate change and natural climatic oscillations. Temperature, in particular, was shown to alter the timing of reproduction and migrations, age at maturity and juvenile migration, and fitness-related traits such as growth, survival, and fecundity.

• Duffy, J. E., J. S. Lefcheck, R. D. Stuart-Smith, S. A. Navarrete, and G. J. Edgar. 2016. Biodiversity enhances reef fish biomass and resistance to climate change. Proceedings of the National Academy of Sciences of the United States of America 113.22: 6230–6235.

  DOI: 10.1073/pnas.1524465113

  Based on 4,556 global fish surveys, the authors analyze how twenty-five different environmental drivers as well as fish biodiversity affect fish biomass. Key predictors of fish biomass increase were fish species richness, functional diversity, and mean temperature. Temperature increases fish biomass directly, as well as indirectly by increasing fish diversity. In contrast, temperature variability had a negative effect on fish biomass, but this effect was halved in the richest fish communities. Hence, the authors conclude that biodiversity can buffer fish biomass against the effects of climate change.

• Nyboer, E. A., H. Y. Lin, J. R. Bennett, et al. 2021. Global assessment of marine and freshwater recreational fish reveals mismatch in climate change vulnerability and conservation effort. Global Change Biology 27.19: 4799–4824.

  DOI: 10.1111/gcb.15768

  Uses physiological and ecological traits of 415 recreational fisheries species from marine and freshwater habitats to assess their vulnerability to climate change. Finds that >20% of the studied species showed climate change vulnerability, in particular for coral reef fishes and freshwater fishes. Further uses socioeconomic values and conservation efforts to detect potential mismatches between species at risk and conservation efforts, with the analysis covering spatial as well as taxonomic scales.

• Pörtner, H. O., and M. A. Peck. 2010. Climate change effects on fishes and fisheries: Towards a cause-and-effect understanding. Journal of Fish Biology 77.8: 1745–1779.

  DOI: 10.1111/j.1095-8649.2010.02783.x

  Evaluates the potential impacts of changes in CO₂, dissolved O₂, and temperature, as a result of climate change, on the physiology of fishes, and the potential consequences at the population and ecosystem levels. Includes quantitative analyses of the upper and lower thermal tolerances of fishes from different latitudes (and hence environmental temperature). Uses studies from around the world to reveal a relationship between acclimation temperature and thermal tolerance. The effects of ontogeny on thermal tolerances are also evaluated.

• Sampaio, E., C. Santos, I. C. Rosa, et al. 2021. Impacts of hypoxic events surpass those of future ocean warming and acidification. Nature Ecology & Evolution 5.3: 311–321.

  DOI: 10.1038/s41559-020-01370-3

  Meta-analysis for fishes, mollusks, and crustaceans on the effects of ocean warming, acidification, and hypoxia on various traits, including survival, growth, and metabolism. For fishes, the effects of hypoxia on these three traits were consistently negative, across tropical and temperate species as well as life stages. In contrast, the effects of ocean warming and acidification were smaller than for hypoxia or non-significant. The important effects of hypoxia call for multi-stressor designs that include reduced O₂ concentrations.

• Vergés, A., P. D. Steinberg, M. E. Hay, et al. 2014. The tropicalization of temperate marine ecosystems: Climate-mediated changes in herbivory and community phase shifts. Proceedings of the Royal Society B: Biological Sciences 281.1789: 20140846.

  DOI: 10.1098/rspb.2014.0846

  Reviews the extent of range extensions by tropical herbivorous fishes into temperate ecosystems and how they alter these systems through overgrazing of canopy-forming algae and seagrasses, which can lead to habitat phase shifts. Several mechanisms are proposed, relating to functional differences in grazing by tropical versus temperate herbivores, and differences in traits and nutritional value of tropical versus temperate macrophytes.