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Trace metals in populations of freshwater isopods: Influence of biotic and abiotic variables
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Selected Bibliography
23° to 30°N), all radio signals, recoveries and sightings were on the Pacific Coast between 30° and 47°N from 1990-1992. After release and until radio-telemetry data ceased to provide a complete sampling of RHB and CON (after about 6 months), RHB pelicans disappeared at a higher rate than CON; a continuing lower survival of RHB was also indicated from independent sightings of colour-marked pelicans by late 1992. RHB pelicans showed no breeding activity (or even presence or association with breeding colonies) in both years. In contrast, expected proportions of radio-marked CON pelicans were active at breeding colonies in 1990, and the general brown pelican population (which acted as controls in 1991) was active at breeding colonies in 1991. Post-brceding dispersal occurred as expected (mostly to the north) in 1990 and 1991 with CON, RHB pelicans remained sedentary in the SCB for at least 5-6 months in 1990 but dispersed north ahead of CON (as expected for non-breeders) in 1991, apparently in response to building ENSO (El Nino/Southern Oscillation) conditions in the SCE 1991-1992. RHB pelicans (1990) tended to remain farther away from the breeding colonies than CON (1990) in their second postrehabilitation breeding season. At that time, their dispersal behaviour was similar to that expected for non-breeding adults and juveniles. We conclude that oil and/or rescue and treatment result in long-term injury to brown pelicans, and that current efforts do not restore them to breeding condition or normal survivability.
Effects of metal-contaminated soils on the growth, sexual development, and early cocoon production of the earthworm E/sema fetida, with particalar reference to zinc. Spurgeon D. J. and Hopkin S. P. Ecotoxicology Research Group, School of Animal/Microbial Sciences, University of Reading, P.O. Box 228, Reading, RG6 6A J, UK. Ecotoxicol. Environ. Saf, 1996, 35/1 (86-95). Suture. in Engl. Juvenile Eisenia fetida (Savigny) were exposed for 20 weeks to an uncontaminated soil and to soils contaminated with cadmium, copper, lead, and zinc collected from seven sites at different distances from a smelting works at Avonmouth, southwest England. The survival, growth ( = weight after 5 weeks exposure), time to sexual maturation ( = percentages of adults present after 8 weeks), and reproduction ( = number of cocoons produced by the worms) were compared with soil metal concentrations. Of the parameters measured, growth and sexual maturation time had the lowest ECso values. The effects of metalcontaminated soils could be attributed both to the direct toxicity of the metals and to changes in the 'scope for growth' of the exposed worms. A comparison of the results with those of an earlier toxicity test conducted with adult worms indicated that juveniles are more sensitive to metals than adults. Significant toxic effects on the growth and sexual maturation times of juveniles were detected in soils from sites for which no significant effects on the cocoon production of adults could be detected. The greater sensitivity of juvenile worms indicates the importance of considering effects on a variety of life history stages when conducting a risk assessment of the effects of pollutants in soils. Although E.fetida does not occur naturally in soils at Avonmouth, the present study provides evidence to support the suggestion that pollution from the smelter is responsible for the absence of worms within 2 km of the factory. Results presented in this paper, and from previous studies, suggest the observed absence is due to the effects of zinc on the growth and maturation of juveniles and the cocoon production rate of adult worms.
Trace metals in populations of freshwater isopods: influence of biotic and abiotic variables. Van Hattum B., Van Straalen N. M. and Groves H. A.J. Institute for Environmental Studies, Free University, De Boelelaan 1115, 1081 HV Amsterdam, The Netherlands. Arch. Environ. Contam. Toxicol., 1996, 31/3 (303-318). Summ. in Engi. Trace metal levels in water, sediments and freshwater isopods from 28 different water systems in the Netherlands were measured during the period of 1986 to 1989. Distinct element-specific internal distribution patterns were present, with Cd and Cu stored mainly in the hepatopancreas (30-60% of total body burden) and Pb and Zn in the hindgut and exoskeleton with hemolymph. Mean whole-body concentrations of the non-essential elements Cd and Pb in individually analyzed isopods varied over three orders of magnitude between populations. The variability of Zn and Cn were within one order of magnitude differ-
ence. The variability of trace metal levels between populations exceeded within-population variability. Within-population variability was related to seasonal and biological factors such as body weight, sex, reproductive state, and species abundance. The highest concentrations were found in small juvenile animals compared to adults, females compared to males, and Proasellus meridianus compared to Asellus aquaticus. However, after correction for size effects using a powercurve regression model no significant differences remained between sex and species. Seasonal fluctuations accounted for 33-79% of the within population variability. Trace metal levels in isopods were predicted from concentrations in water and sediments in combination with aqueous Ca, CI, D(X~, and sediment characteristics (Org-C, clay, CaCO3) using a multiple regression model. With this predictive model 42--63% of the variance could be explained. In situ determined partitioning coefficients (apparent BCF, biota-sediment BSAF, and sediment-water distribution coefficient K(d)) varied between locations and covaried with factors related to trace metal bioavilability (aqueous Ca, CI and DOC, sediment Org-C, clay, and CaCO3). Especially for Cd and Cu field- derived BCF values were in agreement with previously reported experimental studies. It is concluded, that A. aquaticus may be a suitable candidate-organism for biomonitoring available trace metal levels in littoral freshwater systems. Finally, some practical recommendations are given for future field surveys with freshwater isopods with respect to sample size, allometric standardization, period of sampling and statistical design. Determination of organotin compounds in the foodweb of a shallow freshwater lake in the Netberland& Stab J. A., Traas T. P., Stoomberg G. et al. Dune Water Works, P.O. Box 34, 2270 AA Voorburg, The Netherlands. Arch. Environ. Contain. Toxicol., 1996, 31/3 (319-328). Summ. in Engl. An extensive study on the presence of nine organotin compounds (OT) in a freshwater foodweb was made, using newly developed analytical procedures in order to obtain insight in accumulation and degradation processes. Tributylin (TBT), Triphenyltin (TPT) and their degradation products were detected. Zebra mussels, eel, roach, bream, pike, perch, and pike perch and cormorant showed high OT body concentrations. At the lower trophic levels, phenyitin concentrations were higher in benthic species while butyltin concentrations were higher in pelagic species. This indicates that TBT is passed on primarily via the water, while TPT is passed on to a larger extent via the sediment. At the higher trophic levels, net bioaccumulation of TPT was greater than that of TBT, resulting in relatively higher TPT concentrations. High concentrations of biodegradation products of TBT, but not of TPT, were found in the livers of fish and birds, which indicates that TBT is more easily metabolized than TPT. A comparison with literature data of fish lethal body concentrations revealed that fish in the field may be endangered. With birds, the highest concentrations of OT were present in liver and kidney and not in subcutaneous fat, which confirms that OTs accumulate via different mechanisms than traditional lipophilic compounds. As a whole the OT concentrations found in the foodweb may be considered to be quite alarming. Leeches as in site biomoaltom of chlorinated phenofic compounds. Part 2: Pulp mill investigations. Prahacs S. M., Hall K. J. and Duncan W. Westwater Research Center, Univesity of British Columbia, Vancouver, BC VtT IZ2, Canada. Water Res., 1996, 30/10 (2301-2308). Summ. in Engi. Leeches (Nephelopsis obscura Verrill) were evaluated as in situ biomonitors of chlorinated phenolic compounds in the Fraser River at Prince George, BC, downstream from three bleached kraft pulp mills practising chlorine dioxide (C102) substitution. Five biomonitoring periods, of 7 days duration, were selected to cover a full range of seasonal river conditions. Leeches bioconcentrated tri- and tetrachlorinated phenolics (bioconcentration factors: 465-6000) in proportions similar to those present in both mill effluent and river water. Leeches showed 3,4,5-trichloroguaiacol (3,4,5-TCG) to be the most consistent tracer of bleached kraft mill discharge. Leeches provided direct evidence that increasing CIO2 substitution reduces amounts of chlorinated phenolics accumulated by aquatic organisms, with sharp decreases observed at 0 0 2 levels greater than 90%. This study suggests that leeches could be applied as routine biomonitors for environmental impact monitoring.
Selected Bibliography
23° to 30°N), all radio signals, recoveries and sightings were on the Pacific Coast between 30° and 47°N from 1990-1992. After release and until radio-telemetry data ceased to provide a complete sampling of RHB and CON (after about 6 months), RHB pelicans disappeared at a higher rate than CON; a continuing lower survival of RHB was also indicated from independent sightings of colour-marked pelicans by late 1992. RHB pelicans showed no breeding activity (or even presence or association with breeding colonies) in both years. In contrast, expected proportions of radio-marked CON pelicans were active at breeding colonies in 1990, and the general brown pelican population (which acted as controls in 1991) was active at breeding colonies in 1991. Post-brceding dispersal occurred as expected (mostly to the north) in 1990 and 1991 with CON, RHB pelicans remained sedentary in the SCB for at least 5-6 months in 1990 but dispersed north ahead of CON (as expected for non-breeders) in 1991, apparently in response to building ENSO (El Nino/Southern Oscillation) conditions in the SCE 1991-1992. RHB pelicans (1990) tended to remain farther away from the breeding colonies than CON (1990) in their second postrehabilitation breeding season. At that time, their dispersal behaviour was similar to that expected for non-breeding adults and juveniles. We conclude that oil and/or rescue and treatment result in long-term injury to brown pelicans, and that current efforts do not restore them to breeding condition or normal survivability.
Effects of metal-contaminated soils on the growth, sexual development, and early cocoon production of the earthworm E/sema fetida, with particalar reference to zinc. Spurgeon D. J. and Hopkin S. P. Ecotoxicology Research Group, School of Animal/Microbial Sciences, University of Reading, P.O. Box 228, Reading, RG6 6A J, UK. Ecotoxicol. Environ. Saf, 1996, 35/1 (86-95). Suture. in Engl. Juvenile Eisenia fetida (Savigny) were exposed for 20 weeks to an uncontaminated soil and to soils contaminated with cadmium, copper, lead, and zinc collected from seven sites at different distances from a smelting works at Avonmouth, southwest England. The survival, growth ( = weight after 5 weeks exposure), time to sexual maturation ( = percentages of adults present after 8 weeks), and reproduction ( = number of cocoons produced by the worms) were compared with soil metal concentrations. Of the parameters measured, growth and sexual maturation time had the lowest ECso values. The effects of metalcontaminated soils could be attributed both to the direct toxicity of the metals and to changes in the 'scope for growth' of the exposed worms. A comparison of the results with those of an earlier toxicity test conducted with adult worms indicated that juveniles are more sensitive to metals than adults. Significant toxic effects on the growth and sexual maturation times of juveniles were detected in soils from sites for which no significant effects on the cocoon production of adults could be detected. The greater sensitivity of juvenile worms indicates the importance of considering effects on a variety of life history stages when conducting a risk assessment of the effects of pollutants in soils. Although E.fetida does not occur naturally in soils at Avonmouth, the present study provides evidence to support the suggestion that pollution from the smelter is responsible for the absence of worms within 2 km of the factory. Results presented in this paper, and from previous studies, suggest the observed absence is due to the effects of zinc on the growth and maturation of juveniles and the cocoon production rate of adult worms.
Trace metals in populations of freshwater isopods: influence of biotic and abiotic variables. Van Hattum B., Van Straalen N. M. and Groves H. A.J. Institute for Environmental Studies, Free University, De Boelelaan 1115, 1081 HV Amsterdam, The Netherlands. Arch. Environ. Contam. Toxicol., 1996, 31/3 (303-318). Summ. in Engi. Trace metal levels in water, sediments and freshwater isopods from 28 different water systems in the Netherlands were measured during the period of 1986 to 1989. Distinct element-specific internal distribution patterns were present, with Cd and Cu stored mainly in the hepatopancreas (30-60% of total body burden) and Pb and Zn in the hindgut and exoskeleton with hemolymph. Mean whole-body concentrations of the non-essential elements Cd and Pb in individually analyzed isopods varied over three orders of magnitude between populations. The variability of Zn and Cn were within one order of magnitude differ-
ence. The variability of trace metal levels between populations exceeded within-population variability. Within-population variability was related to seasonal and biological factors such as body weight, sex, reproductive state, and species abundance. The highest concentrations were found in small juvenile animals compared to adults, females compared to males, and Proasellus meridianus compared to Asellus aquaticus. However, after correction for size effects using a powercurve regression model no significant differences remained between sex and species. Seasonal fluctuations accounted for 33-79% of the within population variability. Trace metal levels in isopods were predicted from concentrations in water and sediments in combination with aqueous Ca, CI, D(X~, and sediment characteristics (Org-C, clay, CaCO3) using a multiple regression model. With this predictive model 42--63% of the variance could be explained. In situ determined partitioning coefficients (apparent BCF, biota-sediment BSAF, and sediment-water distribution coefficient K(d)) varied between locations and covaried with factors related to trace metal bioavilability (aqueous Ca, CI and DOC, sediment Org-C, clay, and CaCO3). Especially for Cd and Cu field- derived BCF values were in agreement with previously reported experimental studies. It is concluded, that A. aquaticus may be a suitable candidate-organism for biomonitoring available trace metal levels in littoral freshwater systems. Finally, some practical recommendations are given for future field surveys with freshwater isopods with respect to sample size, allometric standardization, period of sampling and statistical design. Determination of organotin compounds in the foodweb of a shallow freshwater lake in the Netberland& Stab J. A., Traas T. P., Stoomberg G. et al. Dune Water Works, P.O. Box 34, 2270 AA Voorburg, The Netherlands. Arch. Environ. Contain. Toxicol., 1996, 31/3 (319-328). Summ. in Engl. An extensive study on the presence of nine organotin compounds (OT) in a freshwater foodweb was made, using newly developed analytical procedures in order to obtain insight in accumulation and degradation processes. Tributylin (TBT), Triphenyltin (TPT) and their degradation products were detected. Zebra mussels, eel, roach, bream, pike, perch, and pike perch and cormorant showed high OT body concentrations. At the lower trophic levels, phenyitin concentrations were higher in benthic species while butyltin concentrations were higher in pelagic species. This indicates that TBT is passed on primarily via the water, while TPT is passed on to a larger extent via the sediment. At the higher trophic levels, net bioaccumulation of TPT was greater than that of TBT, resulting in relatively higher TPT concentrations. High concentrations of biodegradation products of TBT, but not of TPT, were found in the livers of fish and birds, which indicates that TBT is more easily metabolized than TPT. A comparison with literature data of fish lethal body concentrations revealed that fish in the field may be endangered. With birds, the highest concentrations of OT were present in liver and kidney and not in subcutaneous fat, which confirms that OTs accumulate via different mechanisms than traditional lipophilic compounds. As a whole the OT concentrations found in the foodweb may be considered to be quite alarming. Leeches as in site biomoaltom of chlorinated phenofic compounds. Part 2: Pulp mill investigations. Prahacs S. M., Hall K. J. and Duncan W. Westwater Research Center, Univesity of British Columbia, Vancouver, BC VtT IZ2, Canada. Water Res., 1996, 30/10 (2301-2308). Summ. in Engi. Leeches (Nephelopsis obscura Verrill) were evaluated as in situ biomonitors of chlorinated phenolic compounds in the Fraser River at Prince George, BC, downstream from three bleached kraft pulp mills practising chlorine dioxide (C102) substitution. Five biomonitoring periods, of 7 days duration, were selected to cover a full range of seasonal river conditions. Leeches bioconcentrated tri- and tetrachlorinated phenolics (bioconcentration factors: 465-6000) in proportions similar to those present in both mill effluent and river water. Leeches showed 3,4,5-trichloroguaiacol (3,4,5-TCG) to be the most consistent tracer of bleached kraft mill discharge. Leeches provided direct evidence that increasing CIO2 substitution reduces amounts of chlorinated phenolics accumulated by aquatic organisms, with sharp decreases observed at 0 0 2 levels greater than 90%. This study suggests that leeches could be applied as routine biomonitors for environmental impact monitoring.