Surface-water Acidification and Reproducibility of Sediment Cores from Kejimkujik Lake, Nova Scotia, Canada

Authors: Ginn, Brian1; Stewart, Laura; Cumming, Brian; Smol, John

Source: Water, Air, and Soil Pollution, Volume 183, Numbers 1-4, July 2007 , pp. 15-24(10)

Publisher: Springer

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content

Abstract:

A total of nine sediment cores were collected from the five deep basins of Kejimkujik Lake, located in southwestern Nova Scotia, Canada, in order to track changes related to surface-water acidification and to test reproducibility of results between sediment cores from different basins in a large lake. Present-day and pre-industrial (c. 1850) samples were analyzed from all cores and detailed diatom profiles were undertaken on three cores to determine the timing of acidification. All three detailed diatom profiles show declines in inferred pH starting in the early 1930-1940s. Since the 1940s, diatom-inferred lakewater pH has declined from a background pH of ∼5.8 (± 0.4) to a current diatom-inferred pH of ∼4.9 (± 0.1). This corresponds to the current (2001-2002) range of measured lakewater pH = 4.7-5.2 with a mean pH = 4.9. Species diversity of diatoms also declines markedly in all cores with the Hill's N2 index decreasing from ∼5 to near 1. The pre-impact diatom assemblages were dominated by Aulacoseira spp. and have since changed to dominance by Asterionella ralfsii var. americana (>45 μm). All nine sediment cores showed similar changes in diatom assemblages, diatom-inferred pH, and timing of the onset of acidification. Thus, paleolimnological inferences from deepwater sediment cores were highly reproducible in this large, morphometrically complex lake system.

Keywords: Acidic deposition; Core reproducibility; Kejimkujik Lake; Long-range transport of airborne pollutants; Nova Scotia; Surface-water acidification; Diatoms; Paleolimnology

Document Type: Research article

DOI: 10.1007/s11270-006-9311-y

Affiliations: 1: Email: ginnb@biology.queensu.ca

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$47.00 plus tax      Refund Policy

 

OR

Back to top

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages.
Page Help Click here for Page Help
Shopping cart
Tools
Sign in






Need to register?
Sign up here
Text size: A | A | A | A