Short and medium chain polychlorinated n-alkanes (sPCAs and mPCAs) were measured in top predatory fish from nine freshwater bodies across Canada in 2010-2011. Maximum sPCA concentrations were measured in brook trout from Kejimikujik Lake in Nova Scotia (10±8 ng g(-1) wet weight) while the lowest concentrations were found in lake trout from Kusawa Lake in the Yukon (2±3 ng g(-1) wet weight). The presence of sPCAs in fish from these sites is strongly suggestive of long range atmospheric transport, given the absence of known point sources. The highest mPCA concentrations (11-12 ng g(-1) wet weight) were found in lake trout from Lakes Huron, Erie and Ontario. These results showed that fish from sites impacted mostly by atmospheric sources contained higher concentrations of sPCAs than mPCAs while the opposite was observed in sites impacted by industrialization. C12H20Cl6, C12H19Cl7, C14H24Cl6 and C14H23Cl7 were the most abundant homologue groups observed. Lake trout from Lake Huron showed a markedly different sPCA homologue profile, characterized by higher abundances of C11H15Cl9 and C12H17Cl9, indicating local sources. Principal components analysis of sPCA homologues abundances showed that C12H20Cl6, C12H19Cl7, C11H18Cl6, C11H17Cl7 were associated with lakes influenced by atmospheric sources while C11H16Cl8, C12H18Cl8, C11H15Cl9, C12H17Cl9 were associated with sites influenced by urban/industrial sources. Finally, concentrations of sPCAs in Lake Ontario lake trout collected in 2011 decreased 6.6-fold compared to 2001, however no significant differences were observed for mPCAs.
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http://dx.doi.org/10.1016/j.chemosphere.2015.01.016 | DOI Listing |
Biol Lett
January 2025
Department of Forestry and Natural Resources, Purdue University, Forestry Building, 195 Marsteller Street, West Lafayette, IN 47907, USA.
Temperate fishes often spawn in response to environmental cues, such as temperature, thereby facilitating larval emergence concurrent with suitable biotic and abiotic conditions, such as plankton blooms. Climatic changes may alter the reproductive phenology of spring- and autumn-spawning freshwater fish populations. Such effects may depend on the sensitivity of reproductive phenology to ambient temperatures.
View Article and Find Full Text PDFBiology (Basel)
December 2024
Laboratory of Experimental Ecology and Aquaculture, Department of Biology, University of Rome "Tor Vergata", Via Cracovia 1, 00133 Rome, Italy.
Due to their involvement in pathogen-mediated immune responses, the hypervariable genes of the Major Histocompatibility Complex (MHC) have become a paradigm for investigating the evolution and maintenance of genetic (adaptive) diversity, contextually providing insight into the viability of wild populations, which is meaningful for conservation. Here, we provide the first preliminary characterization of MHC polymorphism and evolution in trouts from Albania, a known hotspot of Salmonid diversity harboring ecologically and phylogenetically distinct native (threatened) taxa. Overall, 36 trout-including Lake Ohrid-endemic and , and both riverine and lacustrine native brown trout (the complex) from the Drin-Skadar drainage-were genotyped at the MHC- locus through next-generation amplicon sequencing.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Toxicology Centre, University of Saskatchewan, Saskatoon S7N 5B3, Canada.
-(1,3-Dimethylbutyl)-'-phenyl--phenylenediamine-quinone (6PPD-Q) is a rubber-tire derivative which leaches into surface waters from roadway runoff, from tire particles and has been identified as a possible driver of urban runoff mortality syndrome in coho salmon. Sensitivity to this toxicant is highly variable across fish species and life stages. With environmental concentrations meeting or exceeding toxicity thresholds in sensitive fishes, the potential for ecologically relevant effects is significant.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montreal, QC, H4B 1R6, Canada.
Intraspecific variation is important for species' long-term persistence in changing environments. Conservation strategies targeting intraspecific variation often rely on the identification of management or policy units below the species level based on biological differences among populations. To identify management units, this paper examines intraspecific divergence of Lake Trout (Salvelinus namaycush) in Great Slave Lake (GSL), Canada, using low-coverage whole-genome sequencing data.
View Article and Find Full Text PDFEvol Dev
March 2025
Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
The evolution of adaptive phenotypic divergence requires heritable genetic variation. However, it is underappreciated that trait heritability is molded by developmental processes interacting with the environment. We hypothesized that the genetic architecture of divergent functional traits was dependent on age and foraging environment.
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