Download or read book Diatom Community Responses to Water Quality Improvements in Lakes Recovering from Acidification and Metal contamination Near Wawa Ontario Canada written by Christine Mary Greenaway and published by . This book was released on 2009 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to sulphur dioxide emission reductions in North America and Europe, there has been a recent shift in research focus towards understanding ecosystem recovery. Evidence for reversibility in the effects of acidification on lake ecosystems within North America has been, for the most part, constrained to a single locality (Sudbury, Ontario). Lakes in a fume-kill area near Wawa, Ontario, present a new and rare opportunity for studying potentially rapid chemical and biological recovery patterns from extreme acidification. Several lakes acidified (pH ~3) during a period of local iron sintering from 1939 to 1998, and although minimal historical data are available, striking biological recovery has recently been observed. This study used paleolimnological techniques to track diatom (class Bacillariophyceae) responses to historical water quality changes in five fume-kill lakes near Wawa. Prior to the onset of iron sintering, the sediment-recorded diatom assemblages were dominated by species that are typically found in circumneutral or slightly alkaline lakes. Following the known occurrence of lake acidification, there was a striking shift in the sediment record towards dominance by acid- and metal-tolerant species. Water quality of the fume-kill lakes has since improved (i.e. pH has increased from ~3 to ~7 and metal concentrations have decreased). In four of the five lake cores, this was reflected by a decrease in the relative abundance of acid-tolerant species. Surprisingly, diatom communities were not progressing towards pre-disturbance species assemblages. Factors impeding the return of native species might include metal enrichment in surface sediment and potentially altered lake thermal regimes Documenting and understanding recovery trajectories is necessary to help lake managers evaluate policy decisions regarding the efficacy of emission reduction programs and mitigation measures. This thesis provides evidence from one location in addition to Sudbury that the ecological effects of severe lake acidification can be reversed if SO2 emissions are sufficiently reduced. It also further demonstrates the complexity of recovery patterns in acidified and metal-contaminated lakes.

Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2012-04 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Diatoms written by John P. Smol and published by Cambridge University Press. This book was released on 2010-09-30 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: This much revised and expanded edition provides a valuable and detailed summary of the many uses of diatoms in a wide range of applications in the environmental and earth sciences. Particular emphasis is placed on the use of diatoms in analysing ecological problems related to climate change, acidification, eutrophication, and other pollution issues. The chapters are divided into sections for easy reference, with separate sections covering indicators in different aquatic environments. A final section explores diatom use in other fields of study such as forensics, oil and gas exploration, nanotechnology, and archaeology. Sixteen new chapters have been added since the first edition, including introductory chapters on diatom biology and the numerical approaches used by diatomists. The extensive glossary has also been expanded and now includes over 1,000 detailed entries, which will help non-specialists to use the book effectively.

Download or read book Early Biotic Responses to Advancing Lake Acidification written by George R. Hendrey and published by Butterworth-Heinemann. This book was released on 1984 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Good,No Highlights,No Markup,all pages are intact, Slight Shelfwear,may have the corners slightly dented, may have slight color changes/slightly damaged spine.

Download or read book Heavy Metals in Agricultural Lands Receiving Chemical Sewage Sludges written by Canada-Ontario Agreement on Great Lakes Water Quality and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Importance of Water Colour in Determining Contemporary Diatom Assemblages and the Implications on Down core PH Reconstruction written by Howell, Geoffery and published by . This book was released on 1986 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toxic Contamination in Large Lakes written by Norbert W. Schmidtke and published by CRC-Press. This book was released on 1988-01-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every notable aspect of Toxic Contamination in Large Lakes is examined by known experts from every continent. Authors represent the U.S. and Canada, Argentina, Sweden, USSR, Israel, Great Britain, Japan, China, The Netherlands, Germany, Kenya, Austria. Authors represent the entire spectrum-academia, government, and industry. The first published work offer such a diverse and complete examination of this subject, it provides valuable information and data for today and tomorrow-and the basis for stimulating new research. Chapters in this work were reviewed and carefully edited, after initial presentation at the World Conference on Large Lakes held May 18-21, 1986 at Mackinac Island, Michigan. It presents a wealth of information...a resource for continued use over the years...and should do much to stimulate further study. This vital work is especially of interest to environmental scientists and toxicologists, fisheries professionals, researchers, aquatic resource managers, ecologists, biologists, chemists, and engineers. Every science or engineering library with a water interest should have this notable reference.

Download or read book Relations of Water Quality Land Use Buffers and Diatom Communities of Connected Depressions with in Cache River Watershed Arkansas USA written by David Robert Lawless Burge and published by . This book was released on 2014 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heavy Metals in Agricultural Lands Receiving Chemical Sewage Sludges written by Canada-Ontario Agreement on Great Lakes Water Quality and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heavy Metals in Agricultural Lands Receiving Chemical Sewage Sludges written by Canada-Ontario Agreement on Great Lakes Water Quality and published by . This book was released on 1975 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acid Rain Abstracts written by and published by . This book was released on 1987 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical and Chemical Response of Small North Temperate Lakes to Recovery From Acidification and Climate Change written by Amanda Gavin and published by . This book was released on 2018 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Influence of Selected Water Chemistry Variables on Three Experimental Diatom Communities in an Abandoned Acid Mine Lake written by Kris B. Erickson and published by . This book was released on 1994 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Acid Rain Index written by and published by . This book was released on 1985 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparison Between Diatom Inferred Ph Changes and Diatom Populations in Brownwater and Clearwater Lakes written by John Ciolfi and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to determine whether clearwater and brownwater lakes differed in their rate of acidification as inferred by subfossil diatoms analyzed in recent downcore sediments. Differences between associations of diatom populations in brownwater and clearwater environments were characterized. Sediment cores were taken from four lakes located north and east of Lake Superior, near Wawa, Ontario. Two of these lakes were humicrich, brownwater lakes ( lakes U1 and CB2). The two other lakes were clearwater lakes ( lakes Xl and CF). The regression of Nygaard log index-alpha for surficial diatom sediments on observed pH ( Inferred pH = 6.57 - 0.82 log index-alpha ), was utilized to infer lake pH in recent sediments of these lakes. Upon analyzing the downcore diatoms, it was discovered that no significant change, in downcore diatom inferred pH, could be detected in the two brownwater lakes. In contrast, the two clearwater lakes showed significant shifts in downcore diatom inferred pH. In one of these lakes, pH had dropped from 5.3 to 4.5, in the top 9.0 cm of the core, while in the second lake, pH had dropped from 5.4 to 5.0 in the top 1.5 cm of the core. These findings suggested that humic substances, found in brownwater lakes, imparted a buffering capacity to these lake waters. In the clearwater lakes, the decrease in pH was very probably a consequence of acid precipitation. The Ambrosia rise ( circa 1890 ) occurred at the same depth in both brownwater lakes ( 11.0 - 12.0 cm). In both clearwater lakes, the Ambrosia rise occurred at a depth of 14.0 - 15.0 cm. This suggested a lower sedimentation rate in the brownwater lakes. pH influenced the total percentage composition of diatom pH indicator groups. Greater numbers of alkaliphilous taxa were found in less acidic lakes ( e.g. Lake Ul ), While greater numbers of acidloving forms were found in highly acidic lakes ( e.g. Lake Xl ). There was a greater abundance of indifferent forms in the brownwater lakes, than in the clearwater lakes. A number of diatom genera and species were found to be associated with either clearwater or brownwater conditions. The centric diatom, ~elosira distans, significantly increased in abundance in the recent sediments of both clearwater lakes. This may be indicating a shift toward a more oligotrophic state within these acidic, clearwater lakes. This study suggested that a pH index based on subfossil diatoms may be a sensitive indicator of changing lake pH. This study also indicated that humic substances may playa more important role, than previously acknowledged, in controlling the pH dynamics of lake waters, and in determining diatom populations.

Download or read book The Development of a Diatom based Index of Biotic Integrity to Assess Water Quality of Texas Streams written by Heather Foster and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water pollution is increasing as water availability is decreasing in Texas, causing an immediate need for more and multi-pronged approaches to water quality monitoring. Indices of Biotic Integrity (IBIs) are a promising rapid method to assess water pollution levels, and some have been previously produced for urban streams in Texas. However, many small rural streams remain understudied. Diatoms are excellent candidates for an IBI due to their abundance, ubiquity, species-specific environmental optima, species-identifiable frustule, and rapid generational turnover. These characteristics of diatoms are ideal for detecting the long-term effects of environmental pollutants on a stream community. The objective of this investigation was to construct an IBI for sixteen rural streams in north-central Texas. During this process three hypotheses will be tested: 1) Diatom assemblages will differ between streams that have varying water chemistry parameters, 2) Diatom assemblages at the same site will vary between seasons, 3) Diatom assemblages will be significantly different among the three river basins as a reflection of water chemistry parameters and seasonal changes. Rock and water samples were collected in spring and summer of 2018 to account for seasonal variability in the diatom assemblage. Water chemistry measurements for pH, DO, temperature, conductivity, and stream velocity were taken during sample collection and TN and TP were analyzed in lab. Diatoms were chemically digested, then counted and identified using light microscopy. Descriptive analyses included several biodiversity indices like species richness, Simpson Index, Shannon diversity, evenness, and equitability. The biodiversity indices support the first hypothesis showing that all sites with differing environmental variables had varying species richness, diversity, and evenness. T-tests of assemblages were statistically significant differences in assemblages between seasons, supporting the second hypothesis at species-level seasonal differences in diversity, though not genus-level differences. Canonical correspondence analysis of sites within each river basin were used to correlate diatom species to environmental parameters. Four IBIs, one for each river basin, and a general IBI which combined all diatom data, were constructed with indicator values that represent the environmental sensitivity or tolerance of a genus. The IBIs were applied to some of the site data. A one-way ANOVA performed on the IBI scores did not support any significant differences between the different IBI scores. Therefore, the third hypothesis was not supported, and moreover was irrelevant to the application of IBI construction because of the focus of genus-level data.

Download or read book Life in Extreme Environments written by Ricardo Amils Pibernat and published by Springer Science & Business Media. This book was released on 2007-07-21 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an intriguing look at how life can adapt to many different extreme environments. It addresses the limits for life development and examines different strategies used by organisms to adapt to different extreme environments.