ISSN:
1573-3017
Keywords:
acclimation
;
grass shrimp
;
complex mixtures
;
metals
;
PAHs
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract In acclimation, a pre-exposure to a sublethal level of a contaminant results in an increased resistance in a subsequent exposure to a higher concentration of this contaminant. This research, using the grass shrimp Palaemonetes pugio as a model species, compared the occurrence of acclimation to individual contaminants to that for contaminant mixtures. Grass shrimp collected from Pass Fourchon (a produced-water discharge site with highly-elevated sediment PAH levels as well as elevated metal levels) and conspecifics collected from a nearby control site did not differ in resistance in laboratory exposures to Pass Fourchon sediment. Similarly, grass shrimp collected from the control area and kept for two weeks in enclosures at different sites along the pollution gradient in Pass Fourchon, did not differ in resistance in subsequent laboratory exposures to contaminated sediment. To investigate if these absences of acclimation could be explained by contamination complexity, pre-exposures were then conducted in the laboratory, where specific metals and PAHs in solution were used instead of field-collected contaminated sediments. Typical acclimation responses (an increased resistance at low pre-exposure levels, declining to a reduced resistance at higher pre-exposure levels) were observed for zinc and for naphthalene. No acclimation was observed for phenanthrene, for the combination of zinc and naphthalene, or for a mixture of three metals and three PAHs. These results indicate that acclimation may become less likely as the number of contaminants increases. Potential mechanisms for such a pattern are that one contaminant may inhibit the detoxification of another contaminant, that the energetic requirements (for repair/detoxification) for exposure to one contaminant may compete with those for another contaminant, or that increases in resistance for some contaminants may be offset by decreases in resistance for other contaminants.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008929215781
