Next Article in Journal
Remote Sensing and Geosciences for Archaeology
Next Article in Special Issue
Low Cost, Lightweight Gravity Coring and Improved Epoxy Impregnation Applied to Laminated Maar Sediment in Vietnam
Previous Article in Journal
Mapping of Cold-Water Coral Carbonate Mounds Based on Geomorphometric Features: An Object-Based Approach
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle
Geosciences 2018, 8(2), 40; https://doi.org/10.3390/geosciences8020040

Possible Sediment Mixing and the Disparity between Field Measurements and Paleolimnological Inferences in Shallow Iowa Lakes in the Midwestern United States

School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611, USA
*
Author to whom correspondence should be addressed.
Received: 11 December 2017 / Revised: 10 January 2018 / Accepted: 16 January 2018 / Published: 24 January 2018
(This article belongs to the Special Issue New Theoretical and Applied Advances in Paleolimnology)
View Full-Text   |   Download PDF [2094 KB, uploaded 24 January 2018]   |  

Abstract

Field measurements of water quality in Iowa lakes contradict paleolimnological studies that used 210Pb dating techniques in 33 lakes to infer accelerating eutrophication and sediment accumulation in recent decades. We tested this hypothesis by analyzing a series of water quality measurements taken in 24 of these lakes during the period 1972–2010. There was little change in the trophic state variables. Total phosphorus and algal chlorophylls did not increase, and Secchi depths did not decrease with no evidence that the lakes had become more eutrophic. Changes in daily sediment loads in the Raccoon River also did not match the paleolimnological inferred rates of soil erosion for the period 1905–2005, and an independent estimate of soil erosion rates showed a decline of 40% in the 1977 to 2012 period rather than an increase. We hypothesized that sediment mixing by benthivorous fish could be responsible for violating the basic assumption of 210Pb sediment dating that the sediments are not disturbed once they are laid down. We developed a mathematical model that demonstrated that sediment mixing could lead to false inferences about sediment dates and sediment burial rates. This study raises the possibility that sediment mixing in Iowa lakes and similar shallow, eutrophic lakes with benthivorous fish may cause significant sediment mixing that can compromise dating using 210Pb dating of sediment cores. View Full-Text
Keywords: 210Pb dating; paleolimnology; eutrophication; carbon burial; bioturbation; sediment mixing; diatom-inferred phosphorus 210Pb dating; paleolimnology; eutrophication; carbon burial; bioturbation; sediment mixing; diatom-inferred phosphorus
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Bachmann, R.W.; Hoyer, M.V.; Canfield, D.E. Possible Sediment Mixing and the Disparity between Field Measurements and Paleolimnological Inferences in Shallow Iowa Lakes in the Midwestern United States. Geosciences 2018, 8, 40.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Geosciences EISSN 2076-3263 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top