AUTHOR=McCarthy Gretchen J. , Ray Nicholas E. , Fulweiler Robinson W. TITLE=Greenhouse Gas Emissions From Native and Non-native Oysters JOURNAL=Frontiers in Environmental Science VOLUME=7 YEAR=2019 URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2019.00194 DOI=10.3389/fenvs.2019.00194 ISSN=2296-665X ABSTRACT=

Non-native species introductions are associated with a range of ecosystem changes such as habitat destruction, competition with native species, and biodiversity losses. Less well known is the role non-native species play in altering biogeochemical processes, such as the emission of greenhouse gases (GHGs). In this study we used laboratory incubations to compare seasonal (spring, summer, fall) emissions of the GHGs nitrous oxide (N₂O), methane (CH₄), and carbon dioxide (CO₂) from native (Crassostrea virginica) and non-native (Ostrea edulis) oysters collected from a northern temperate estuary (Duxbury Bay, Massachusetts, USA). We observed strong seasonal signals in GHG fluxes, where C. virginica was the higher GHG emitter, and produced on average twice as much N₂O (0.39 nmol g⁻¹ dry tissue weight hr⁻¹) and 20 times as much CH₄ (1.31 nmol g DTW⁻¹ hr⁻¹) compared to O. edulis (0.16 nmol N₂O g DTW⁻¹ hr⁻¹ and 0.07 nmol CH₄ g DTW⁻¹ hr⁻¹). C. virginica also had significantly (p < 0.001) higher summer maximum production rates of CO₂ compared to O. edulis (53.4 μmol g DTW⁻¹ hr⁻¹ and 45.4 μmol g DTW⁻¹ hr⁻¹, respectively). Despite these differences, chlorophyll-a consumption rates between the species were similar (p = 0.95). These results suggest that the non-native O. edulis is a lower GHG emitter than the native C. virginica and highlight that, at least in terms of GHG emissions, this non-native species introduction may not be detrimental to the environment.