Cover Image

Paleolimnological assessment of nutrient enrichment on diatom assemblages in a priori defined nitrogen- and phosphorus-limited lakes downwind of the Athabasca Oil Sands, Canada

Kathleen R. Laird, Biplob Das, Brittany Hesjedal, Peter R. Leavitt, Graham R. Mushet, Kenneth A. Scott, Gavin L. Simpson, Bjorn Wissel, Jared Wolfe, Brian F. Cumming
  • Biplob Das
    Saskatchewan Water Security Agency, Canada
  • Brittany Hesjedal
    University of Regina, Canada
  • Peter R. Leavitt
    University of Regina, Canada
  • Graham R. Mushet
    Queen's University, Canada
  • Kenneth A. Scott
    Saskatchewan Ministry of Environment, Canada
  • Gavin L. Simpson
    University of Regina, Canada
  • Bjorn Wissel
    University of Regina, Canada
  • Jared Wolfe
    University of Regina, Canada
  • Brian F. Cumming
    Queen’s University, Canada

Abstract

As the industrial footprint of the Athabasca Oil Sands Region (AOSR) continues to expand, concern about the potential impacts of pollutants on the surrounding terrestrial and aquatic ecosystems need to be assessed. An emerging issue is whether recent increases in lake production downwind of the development can be linked to AOSR activities, and/or whether changing climatic conditions are influencing lake nutrient status. To decipher the importance of pollutants, particularly atmospheric deposition of reactive nitrogen (Nr), and the effects of climate change as potential sources of increasing lake production, lakes from both within and outside of the nitrogen deposition zone were analyzed for historical changes in diatom assemblages. Lake sediment cores were collected from a priori defined nitrogen (N) - and phosphorus (P) - limited lakes within and outside the N plume associated with the AOSR. Diatom assemblages were quantified at sub-decadal resolution since ca. 1890 to compare conditions prior to oil sands expansion and regional climate warming, to the more recent conditions in each group of lakes (Reference and Impacted, N- and P-limited lakes). Analyses of changes in assemblage similarity and species turnover indicates that changes in diatom assemblages were minimal both within and across all lake groups.  Small changes in percent composition of planktonic taxa, particularly small centric taxa (Discostella and Cyclotella species) and pennate taxa, such as Asterionella formosa and Fragilaria crotonensis, occurred in some of the lakes. While these changes were consistent with potential climate effects on algal growth, water column stability and other factors; the timing and direction of biotic changes were variable among sites suggesting that any apparent response to climate was lake dependent. The absence of a consistent pattern of diatom changes associated with receipt of reactive nitrogen or intrinsic nutrient-limitation status of the lake suggest that downwind AOSR emissions had no demonstrable effect on diatom composition. 

Keywords

Athabasca oil sands; nitrogen deposition; diatom assemblages; nutrient limitation.

Full Text:

PDF
Supplementary
Submitted: 2016-11-02 14:21:42
Published: 2017-04-14 00:00:00
Search for citations in Google Scholar
Related articles: Google Scholar
Abstract views:
821

Views:
PDF
327
Supplementary
76

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM


Copyright (c) 2017 Kathleen R. Laird, Biplob Das, Brittany Hesjedal, Peter R. Leavitt, Graham R. Mushet, Kenneth A. Scott, Gavin L. Simpson, Bjorn Wissel, Jared Wolfe, Brian F. Cumming

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
 
© PAGEPress 2008-2017     -     PAGEPress is a registered trademark property of PAGEPress srl, Italy.     -     VAT: IT02125780185