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Effects of nutrient load on microbial activities within a seagrass-dominated ecosystem: implications of changes in seagrass blue carbon
journal contribution
posted on 2017-04-15, 00:00 authored by S Liu, Z Jiang, Y Wu, J Zhang, I Arbi, F Ye, X Huang, Peter MacreadiePeter MacreadieNutrient loading is a leading cause of global seagrass decline, triggering shifts from seagrass- to macroalgal-dominance. Within seagrass meadows of Xincun Bay (South China Sea), we found that nutrient loading (due to fish farming) increased sediment microbial biomass and extracellular enzyme activity associated with carbon cycling (polyphenol oxidase, invertase and cellulase), with a corresponding decrease in percent sediment organic carbon (SOC), suggesting that nutrients primed microorganism and stimulated SOC remineralization. Surpisingly, however, the relative contribution of seagrass-derived carbon to bacteria (δ(13)Cbacteria) increased with nutrient loading, despite popular theory being that microbes switch to consuming macroalgae which are assumed to provide a more labile carbon source. Organic carbon sources of fungi were unaffected by nutrient loading. Overall, this study suggests that nutrient loading changes the relative contribution of seagrass and algal sources to SOC pools, boosting sediment microbial biomass and extracellular enzyme activity, thereby possibly changing seagrass blue carbon.
History
Journal
Marine pollution bulletinVolume
117Issue
1-2Pagination
214 - 221Publisher
ElsevierLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
0025-326XeISSN
1879-3363Language
engPublication classification
C Journal article; C1 Refereed article in a scholarly journalCopyright notice
2017, ElsevierUsage metrics
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