Abstract
Sublethal concentrations of pollutants may compromise fish, resulting in increased susceptibility to endemic pathogens. To test this hypothesis, juvenile chinook salmon (Oncorhynchus tshawytscha) were exposed to sublethal levels of esfenvalerate or chlorpyrifos either alone or concurrently with infectious hematopoietic necrosis virus (IHNV). Three trials were performed with fish exposed to concentrations of IHNV between 0.8 × 102 and 2.7 × 106 plaque-forming units/ml and to 5.0 μg/L of chlorpyrifos or 0.1 μg/L of esfenvalerate. The presence and concentration of IHNV in dead fish were assayed by virus isolation and plaque assay techniques, respectively. Among groups exposed to both esfenvalerate and IHNV, 83% experienced highly significant (p < 0.001) mortality, ranging from 20 to 90% at 3 d post-virus exposure, and cumulatively died from 2.4 to 7.7 d sooner than fish exposed to IHNV alone. This trend was not seen in any other treatment group. Virus assays of dead fish indicate a lethal synergism of esfenvalerate and IHNV. Chlorpyrifos had no observed effect on total mortality or IHNV susceptibility. The present results suggest that accepted levels of pollutants may be seemingly nonlethal to fish but, in fact, be acting synergistically with endemic pathogens to compromise survivorship of wild fish populations through immunologic or physiologic disruption.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1766-1772 |
| Number of pages | 7 |
| Journal | Environmental Toxicology and Chemistry |
| Volume | 24 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1 2005 |
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Keywords
- Esfenvalerate
- Infectious hematopoietic necrosis virus
- Pollution
- Salmon
- Synergy
ASJC Scopus subject areas
- Environmental Chemistry
- Health, Toxicology and Mutagenesis
Cite this
Synergistic effects of esfenvalerate and infectious hematopoietic necrosis virus on juvenile chinook salmon mortality. / Clifford, Mark A.; Eder, Kai J.; Werner, Ingeborg; Hedrick, Ronald.
In: Environmental Toxicology and Chemistry, Vol. 24, No. 7, 01.07.2005, p. 1766-1772.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synergistic effects of esfenvalerate and infectious hematopoietic necrosis virus on juvenile chinook salmon mortality
AU - Clifford, Mark A.
AU - Eder, Kai J.
AU - Werner, Ingeborg
AU - Hedrick, Ronald
PY - 2005/7/1
Y1 - 2005/7/1
N2 - Sublethal concentrations of pollutants may compromise fish, resulting in increased susceptibility to endemic pathogens. To test this hypothesis, juvenile chinook salmon (Oncorhynchus tshawytscha) were exposed to sublethal levels of esfenvalerate or chlorpyrifos either alone or concurrently with infectious hematopoietic necrosis virus (IHNV). Three trials were performed with fish exposed to concentrations of IHNV between 0.8 × 102 and 2.7 × 106 plaque-forming units/ml and to 5.0 μg/L of chlorpyrifos or 0.1 μg/L of esfenvalerate. The presence and concentration of IHNV in dead fish were assayed by virus isolation and plaque assay techniques, respectively. Among groups exposed to both esfenvalerate and IHNV, 83% experienced highly significant (p < 0.001) mortality, ranging from 20 to 90% at 3 d post-virus exposure, and cumulatively died from 2.4 to 7.7 d sooner than fish exposed to IHNV alone. This trend was not seen in any other treatment group. Virus assays of dead fish indicate a lethal synergism of esfenvalerate and IHNV. Chlorpyrifos had no observed effect on total mortality or IHNV susceptibility. The present results suggest that accepted levels of pollutants may be seemingly nonlethal to fish but, in fact, be acting synergistically with endemic pathogens to compromise survivorship of wild fish populations through immunologic or physiologic disruption.
AB - Sublethal concentrations of pollutants may compromise fish, resulting in increased susceptibility to endemic pathogens. To test this hypothesis, juvenile chinook salmon (Oncorhynchus tshawytscha) were exposed to sublethal levels of esfenvalerate or chlorpyrifos either alone or concurrently with infectious hematopoietic necrosis virus (IHNV). Three trials were performed with fish exposed to concentrations of IHNV between 0.8 × 102 and 2.7 × 106 plaque-forming units/ml and to 5.0 μg/L of chlorpyrifos or 0.1 μg/L of esfenvalerate. The presence and concentration of IHNV in dead fish were assayed by virus isolation and plaque assay techniques, respectively. Among groups exposed to both esfenvalerate and IHNV, 83% experienced highly significant (p < 0.001) mortality, ranging from 20 to 90% at 3 d post-virus exposure, and cumulatively died from 2.4 to 7.7 d sooner than fish exposed to IHNV alone. This trend was not seen in any other treatment group. Virus assays of dead fish indicate a lethal synergism of esfenvalerate and IHNV. Chlorpyrifos had no observed effect on total mortality or IHNV susceptibility. The present results suggest that accepted levels of pollutants may be seemingly nonlethal to fish but, in fact, be acting synergistically with endemic pathogens to compromise survivorship of wild fish populations through immunologic or physiologic disruption.
KW - Esfenvalerate
KW - Infectious hematopoietic necrosis virus
KW - Pollution
KW - Salmon
KW - Synergy
UR - http://www.scopus.com/inward/record.url?scp=21444456035&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=21444456035&partnerID=8YFLogxK
U2 - 10.1897/04-463R.1
DO - 10.1897/04-463R.1
M3 - Article
VL - 24
SP - 1766
EP - 1772
JO - Environmental Toxicology and Chemistry
JF - Environmental Toxicology and Chemistry
SN - 0730-7268
IS - 7
ER -