Overfishing, nutrient-fuelled hypoxia and habitat destruction have reduced oyster populations to a fraction of their former abundance. Over the past two decades there has been a widespread effort to restore oyster reefs and develop oyster aquaculture. Yet it remains unclear how re-introduction of large oyster populations will change coastal biogeochemistry. Of particular interest is whether oysters may help offset excess nitrogen loading, which is responsible for widespread coastal water quality degradation, low oxygen conditions and biodiversity declines. Here we used a meta-analysis approach to assess how oysters alter inorganic nutrient cycling, with a focus on nitrogen removal. Additionally, we examined how oysters alter greenhouse gas emissions. We demonstrate that oysters enhance removal of excess nitrogen by stimulating denitrification, promote efficient nutrient recycling and may have a negligible greenhouse gas footprint. Further, oyster reefs and oyster aquaculture appear to have similar biogeochemical function, suggesting the potential for sustainable production of animal protein alongside environmental restoration.
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Biodiversity associated with restored small-scale mussel habitats has restoration decision implications
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Opportunities and Challenges for Including Oyster-Mediated Denitrification in Nitrogen Management Plans
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All data used in this study is available in the Figshare repository under the access number https://doi.org/10.6084/m9.figshare.12488753.
The R script used in this meta-analysis is available in the GitHub community repository (https://github.com/nray17/Meta-analysis-oyster-impacts-on-biogeochemistry).
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This work was supported by fellowship funding to N.E.R. and R.W.F. from the Frederick S. Pardee Center for the Study of the Longer Range Future at Boston University. N.E.R. also received support from the Biology Department at Boston University and R.W.F. was supported by a grant from Rhode Island Sea Grant. We thank E. Moothart and T. Condon for assistance with creating the map of study sites.
The authors declare no competing interests.
Peer review information Nature Sustainability thanks Tamar Guy-Haim and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Supplementary Fig. 1, list of studies included in meta-analysis, and Supplementary Tables 1–12.
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Ray, N.E., Fulweiler, R.W. Meta-analysis of oyster impacts on coastal biogeochemistry. Nat Sustain 4, 261–269 (2021). https://doi.org/10.1038/s41893-020-00644-9
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