The toxicity of intact sediments and sediment extracts, from both an uncontaminated site and a site contaminated by pulp-mill effluents, was tested in a five months study. The deposit-feeding amphipod Monoporeia affinis was exposed in soft-bottom flow-through water microcosms. To examine potential toxicity a set of reproduction endpoints was used including fecundity and different embryo aberrations such as malformed eggs. Among extracts, the aliphatic/monoaromatic and diaromatic fractions along with the total extract were shown to cause the highest toxicity measured as malformed eggs, while the polyaromatic fraction caused toxicity at background levels. A comparison between sediment extracts and pulp mill contaminated intact sediment, however, showed no toxicity of the intact sediment. Thus, the extraction procedure seems to increase bioavailability and subsequently toxicity as compared to the intact sediments in situ. In toxicity testing using fractionated extracts of sediments in a toxicity identification evaluation (TIE) procedures, caution should therefore be taken when assessing bioavailable contaminants in contaminated areas. This should be taken in account both in determining remediation priorities as well as in ecological risk assessments.
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http://dx.doi.org/10.1016/j.marpolbul.2005.02.030 | DOI Listing |
J Environ Qual
January 2025
Institute for the Environment, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Population growth in coastal areas increases nitrogen inputs to receiving waterways and degrades water quality. Wetland habitats, including floodplain forests and marshes, can be effective nitrogen sinks; however, little is known about the effects of chronic point source nutrient enrichment on sediment nitrogen removal in tidally influenced coastal systems. This study characterizes enrichment patterns in two tidal systems affected by wastewater treatment facility (WWTF) effluent and assesses the impact on habitat nitrogen removal via denitrification.
View Article and Find Full Text PDFSci Total Environ
December 2024
Physical Ecology Laboratory, Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada. Electronic address:
The effectiveness of riparian vegetation buffers at conserving hyporheic habitats used by freshwater unionid mussels is not well understood. A comparison of sites with intact vs. fragmented vegetation buffers in the east branch of the Sydenham River (Ontario, Canada) revealed differences.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Applied Ecology Research Group, School of Life Sciences, Anglia Ruskin University, Cambridge CB1 1PT, United Kingdom.
Cigarette butts are amongst the most littered single-use plastics on coasts, yet their impacts on marine ecosystems, especially on a community level, are not well understood. Recently, e-cigarettes have become popular and are a novel litter item in marine habitats. Preliminary research indicates that e-liquid can harm individual organisms, but few studies have been done and none on a community level.
View Article and Find Full Text PDFSci Total Environ
December 2024
Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.
Mar Environ Res
November 2024
The Nature Conservancy, Carlton, Victoria, Australia.
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