The relative roles of point and nonpoint phosphorus sources in the eutrophication of Lake Champlain as recorded in sediment cores

Project Author
Issue Date
2018-06-10
Authors
Levine, Suzanne N.
Lini, Andrea
Ostrofsky, Milton L.
Burgess-Grant, Heather
Lami, Andrea
Collyer-Gilles, Elizabeth
Reuter, Daun
Schwarting-Miller, Lindsay
Kamman, Neil
Loading...
Thumbnail Image
Embargo
This version of the article is available for viewing to the public after June 18, 2022.
First Reader
Additional Readers
Keywords
Lake Champlain , eutrophication , paleolimnology , Agriculture , sediment , restoration
item.page.distribution
Abstract
Thirteen sediment cores from Lake Champlain (Vermont-New York- Quebec) were analyzed for sediment accumulation rate and eleven indicators of trophic status to reconstruct eutrophication history and relate it to phosphorus inputs from soil erosion, urban point sources, and agricultural runoff including P extracted from phosphate ore and brought to the catchment in fertilizer and livestock feed. Although the catchment was severely deforested and grazed by sheep and cattle in the 19th century, ten of thirteen sites accumulated excess sediment only in the 20th century, a consequence of slow sediment transport through the catchment. Of the three sites that received extra sediment, one remained oligotrophic, while two exhibited mild eutrophication. All sites underwent eutrophication in the 20th century. Three reached their current trophic status before agriculture's intensification, while point-source P input was maximal (1950–1980), four stayed in the reference state until agriculture intensified in the 1970s, and six responded incrementally first to point and then to agricultural P input. Pigment accumulation rates diminished at the surface of seven cores, evidence that the 1990s expansion of P removal from point sources reduced phytoplankton biomass. Additional water quality improvement depends on P management at the catchment border to balance inputs and outputs, and thus avoid P accumulation in soil that saturates phosphate sorption capacity, increasing the proportion of runoff P that is highly-bioavailable orthophosphate. Erosion control is of lower priority because the P native to the catchment's soil is of relatively low bioavailability, and retention structures do not retain dissolved P.
Description
Chair
Major
Department
Biology
Recorder
License
This article has been selected for publication in Journal of Great Lakes Research (2018) Levine, et al. All rights reserved.
Citation
Levine, S.N., Lini, A., Ofstrofsky, M.L., et al. (2018). The relative roles of point and nonpoint phosphorus sources in the eutrophication of Lake Champlain as recorded in sediment cores. Journal of Great Lakes Research, xx(x): 1-14. doi: 10.1016/j.jglr.2018.06.005.
Version
Final manuscript post peer review, without publisher's formatting or copy editing (postprint)
Honors
Publisher
Elsevier
Series