Winter weather and lake-watershed physical configuration drive phospnorus, iron and manganese dynamics in water and sediment of ice-covered lakes


TitleWinter weather and lake-watershed physical configuration drive phospnorus, iron and manganese dynamics in water and sediment of ice-covered lakes
Publication TypeJournal Article
Year of Publication2017
AuthorsJoung, D, Leduc, M, Ramcharitar, B, Xu, Y, Isles, PDF, Stockwell, JD, Druschel, G, Manley, T, Schroth, AW
JournalLimnology and Oceanography
Volume62
Start Page1620
Issue4
Pagination1620-1635
Date Published2017/03
Abstract

While decreasing occurrence and duration of lake ice cover is well-documented, biogeochemical dynamics in frozen lakes remain poorly understood. Here, we interpret winter physical and biogeochemical time series from eutrophic Missisquoi Bay (MB) and hyper-eutrophic Shelburne Pond (SP) to describe variable drivers of under ice biogeochemistry in systems of fundamentally different lake-watershed physical configurations (lake area, lake : watershed area). The continuous cold of the 2015 winter drove the MB sediment-water interface to the most severe and persistent suboxic state ever documented at this site, promoting the depletion of redox-sensitive phases in sediments, and an expanding zone of bottom water enriched in reactive species of Mn, Fe, and P. In this context, lake sediment and water column inventories of reactive chemical species were sensitive to the severity and persistence of subfreezing temperatures. During thaws, event provenance and severity impact lake thermal structure and mixing, water column enrichment in P and Fe, and thaw capability to suppress redox front position and internal chemical loading. Nearly identical winter weather manifest differently in nearby SP, where the small surface and watershed areas promoted a warmer, less stratified water column and active phytoplankton populations, impacting biogeochemical dynamics. In SP, Fe and P behavior under ice were decoupled due to active biological cycling, and thaw impacts were different in distribution and composition due to SP's physical structure and related antecedent conditions. We find that under ice biogeochemistry is highly dynamic in both time and space and sensitive to a variety of drivers impacted by climate change.

URLhttp://onlinelibrary.wiley.com/doi/10.1002/lno.10521/full
DOI10.1002/lno.10521
Refereed DesignationRefereed
Status: 
Published
Attributable Grant: 
BREE
Grant Year: 
Year2 StatusChanged
Acknowledged VT EPSCoR: 
Ack-Yes
2nd Attributable Grant: 
NEWRnet
2nd Grant Year: 
2nd_Year4
2nd Acknowledged Grant: 
2nd_Ack-Yes