Histologic, immunologic and endocrine biomarkers indicate contaminant effects in fishes of the Ashtabula River

Abstract

The use of fish as sentinels of aquatic ecosystem health is a biologically relevant approach to environmental monitoring and assessment. We examined the health of the Ashtabula River using histologic, immunologic, and endocrine biomarkers in brown bullhead (BB; Ameiurus nebulosus) and largemouth bass (Micropterus salmoides) and compared fish collected from a reference site (Conneaut Creek). Seasonal analysis was necessary to distinguish differences in fish between the two rivers. Overall BB from the Ashtabula River had a lower condition factor and significantly more macrophage aggregates than those from the reference site. Reduced bactericidal and cytotoxic-cell activity was observed in anterior kidney leukocytes from both BB and largemouth bass from the Ashtabula River. Lower plasma thyroxine and triiodo-L-thyronine in both species in the Ashtabula River indicated disruption of the thyroid axis. Differences in physiological biomarker responses were supported by body burden chemical concentrations when data were analyzed on a seasonal basis. The use of two fish species added a level of rigor that demonstrated biological effects were not exclusive to a single species. The results provide strong evidence that contaminants have affected fish in the Ashtabula River, a Great Lakes Area of Concern, and provide a baseline by which to evaluate remediation activities.

Tissue Distribution and Immunomodulation in Channel Catfish (Ictalurus punctatus) Following Dietary Exposure to Polychlorinated Biphenyl Aroclors and Food Deprivation

“…While the effect of food deprivation was generally greater than that for PCB exposure, PCB exposure did decrease bactericidal and oxidative burst activity. This result is consistent with those of previous studies in ictalurids [19,38,54], and suggests that PCB exposure may increase disease susceptibility, which could influence population demography. Notably, bactericidal activity returned to normal seven weeks after the start of a PCB-free diet, suggesting that the effect of PCBs on some immunological responses may be temporary.…”

“…The goal of the PCB exposure phase was to feed fish in the PF and PNF treatments PCB-spiked food until they reached a body burden of 5 mg/kg while feeding fish in the CF and CNF treatments unspiked food. A target concentration of 5 mg/kg was chosen because it is representative of the total body burden found in tissues of wild fish in PCB-contaminated environments [38]. As described below, we intended the PCB exposure phase to last for eight weeks; however, it took 11 weeks for fish in the PF and PNF treatments to reach the target body burden.…”

Micronuclei and other erythrocyte nuclear abnormalities in fishes from the Great Lakes Basin, USA

“…The AOC sites included the lower Ashtabula River located near Ashtabula, Ohio; the Trenton channel of the Detroit River sampled south of Detroit, Michigan; the lower Genesee River sampled near Rochester, New York; the lower Milwaukee River sampled near Milwaukee, Wisconsin and St. Louis Bay sampled near Duluth, Minnesota. Conneaut Creek, near Conneaut, Ohio, has been previously used as a reference site for comparison with the nearby Ashtabula River AOC [Iwanowicz et al, ]. In fall, fish were collected at the Ashtabula and Conneaut sites for a seasonal comparison.…”

Polish Scientists in Fish Immunology: A Short History

“…injection of Aroclor 1238 (a PCB mixture) in brown bullhead, Ameiurus nebulosus , decreased bactericidal activity and circulating antibodies to Edwardsiella ictaluri [ 33 ]. In a field study, Iwanowicz and colleagues showed that brown bullheads in a PCB contaminated river had more macrophage aggregates and a reduced bactericidal and cytotoxic cell activity compared to the same species at a relative clean site [ 34 ]. It is interesting to mention that marked seasonal effects were observed in this field study.…”