O'Beirne MD, Werne JP, Hecky RE, Johnson TC, Katsev S, Reavie ED. Anthropogenic climate change has altered primary productivity in Lake Superior.
Nat Commun 2017;
8:15713. [PMID:
28598413 PMCID:
PMC5472714 DOI:
10.1038/ncomms15713]
[Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 04/21/2017] [Indexed: 11/19/2022] Open
Abstract
Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems.
The impacts of climate change on the Great Lakes' ecosystems compared to historical records are unclear. Here, using paleolimnological evidence, the authors show that Lake Superior experienced a slow increase in productivity throughout the Holocene, but that this rate has increased in the last century.
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