"Scientists - and society in general - are increasingly concerned about climate change and its impact on living resources", states Fabrice Pernet, Ifremer, France. Concerns about food security ensure, "that aquaculture products are increasingly important for human nutrition".
Aquaculture has been the fastest growing food production system over the last five decades, and now produces more seafood than is caught by wild capture fisheries. Its continued growth depends on many factors - space allocation, financing, biosecurity controls - but how will climate change affect the industry?
Together with Howard Browman, Institute of Marine Research, Norway, Pernet wanted to explore the current research on "the potential impacts, adaptation, and mitigation strategies of marine aquaculture in an era of rapid change". This has developed into the latest themed set of articles in ICES Journal of Marine Science, Marine aquaculture in the anthropocene.
The themed set contains 15 articles, including an introduction from Pernet and Browman, The future is now: marine aquaculture in the anthropocene, embracing social complexity in aquaculture carrying capacity estimations, a triple P approach (People, Planet, Profit) approach to seaweed production, and a paper from the Working Group on Scenario Planning on Aquaculture (WGSPA) which asks if ICES member countries have the potential to maintain a sustainable supply of seafood for their populations?
The articles address the impacts of climate change-related factors on aquaculture production and spatial distribution of species-specific aquaculture activities, phenotypic plasticity and adaptation potential of farmed species under climate change, parasitism and predation, adaptive measures for mitigating the impacts of climate change on marine resources, and the sustainable development of aquaculture.
"The most important climate change-related factor facing aquaculture is increasing temperatures", Pernet says, "Temperature has direct effects on the physiology of organisms and their biogeographical distribution, but also indirect effects, such as the increased risk of emergence of pathogens, alteration of trophic networks, interactions between species, and so on."
Aquaculture, to continue its growth, must adapt. Pernet outlines three types of action that are possible, "First, we must anticipate the biogeographical changes in the distribution of species. Second, we must determine if species can adapt to a range of stressors via evolution. Then, the selection of robust phenotypes which are resistant or tolerant to these stressors would be an option. Third, we must consider ecosystem conservation, restoration, or remediation strategies to foster resilience to climate change stressors. These three options are not mutually exclusive and should be considered together."
A potential threat from climate change is the risk of disease which biodiversity can limit. "Macroalgae and plants act as a carbon sink, creating local refugia against acidification for calcifying organisms", notes Pernet, "These examples suggest that a combination of species that interact favorably with each other can mitigate the effects of climate change".
Find the latest themed set Marine aquaculture in the anthropocene in the latest issue of ICES Journal of Marine Science. All articles in this themed set are free to view and download.
Cartoon by Bas Köhler. Click to enlarge.