An in situ bioassay approach was used to determine whether aquatic contaminant stressors in a large Atlantic river ecosystem affect the survival of 3 fish species: the largemouth bass (Micropterus salmoides, juveniles), the fathead minnow (Pimephales promelas, adults), and the robust redhorse (Moxostoma robustum, juveniles). Hatchery-propagated fish were placed into cages to assess site-specific survival in the Yadkin-Pee Dee River of North Carolina and South Carolina, USA. Contaminants were measured in caged fish and sediment and surface water at each site.
View Article and Find Full Text PDFPer- and polyfluoroalkyl substances (PFASs) have attracted scientific and regulatory attention due to their persistence, bioaccumulative potential, toxicity, and global distribution. We determined the accumulation and trophic transfer of 14 PFASs (5 short-chain and 9 long-chain) within the food web of the Yadkin-Pee Dee River of North Carolina and South Carolina, US. Food web components and pathways were determined by stable isotope analyses of producers, consumers, and organic matter.
View Article and Find Full Text PDFEndocrine active compounds (EACs) are pollutants that have been recognized as an emerging and widespread threat to aquatic ecosystems globally. Intersex, the presence of female germ cells within a predominantly male gonad, is considered a biomarker of endocrine disruption caused by EACs. We measured a suite of EACs and assessed their associated impacts on fish intersex occurrence and severity in a large, regulated river system in North Carolina and South Carolina, USA.
View Article and Find Full Text PDFPersistent and bioaccumulative contaminants often reach concentrations that threaten aquatic life by causing alterations in organism behavior and development, disruption of biological processes, reproductive abnormalities, and mortality. The objectives of this research were to determine the aquatic food web structure and trophic transfer and accumulation of contaminants within a riverine ecosystem and identify potential stressors to the health of an imperiled fish, the robust redhorse (Moxostoma robustum) and other species of conservation concern in a large Atlantic Slope (USA) river. Trophic position was determined for food web taxa by stable isotope analyses of representative producers, consumers, and organic matter of the Yadkin-Pee Dee River of North Carolina and South Carolina.
View Article and Find Full Text PDFPhysiological information is rarely used in descriptions of maturity for managed, wild fish species; however, the use of physiological data holds great promise to provide important detail on the complexities of oocyte development and maturity. Investigating southern flounder ()-an overfished commercial and recreational fishery resource-we examined pre-spawn physiological changes in females to provide further detail of the maturation process. Given that adults of this species complete maturation and spawn in unknown offshore locations, information on pre-spawn physiological changes is particularly informative for both size- and age-based patterns of maturity.
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