Laverne Cleveland

Interactive Toxicity of Aluminum and Acidity to Early Life Stages of Brook Trout

Abstract The influences of exposure to aluminum and increased acidity on mortality, growth, behavior, and biochemical responses of brook trout Salvelinus fontinalis were evaluated as a function of developmental stage. Eyed eggs and young brook trout were exposed until 30 d after hatching in proportional diluters to pHs of 4.5, 5.5, and 7.2, with and without aluminum (300 μg/L); 37-d-old brook trout that had been held in experimental control water since hatching were exposed to these same conditions for 30 d. Exposure conditions (i.e., aluminum and calcium concentrations and pH) simulated conditions in some headwater lakes and streams in the northeastern United States. Adverse effects on exposed brook trout generally increased as pH decreased from 7.2 to 4.5 and potentiation of effects by aluminum occurred at pHs of 5.5 to 7.2. However, embryos and fish older than 36 d were more tolerant of acidic conditions and aluminum than were larvae less than 15 d old. We conclude that the adverse effects on mortality...

Toxicity and bioaccumulation of waterborne and dietary selenium in juvenile bluegill (Lepomis macrochirus)

Abstract Juvenile bluegill (Lepomis macrochirus) were exposed to waterborne selenium as a 6:1 mixture of selenate to selenite (as Se) for 60 d and to dietary seleno- l -methionine for 90 d. Measured concentrations of total selenium in the waterborne exposure ranged from 0.16 to 2.8 mg/l, and concentrations of seleno- l -methionine in the test diet ranged from 2.3 to 25.0 mg/kg wet weight. Mortality, body weight, condition factor, swimming and feeding behavior, aggression, and selenium tissue residues were monitored during the tests. Increased mortality at measured concentrations of 0.64 mg Se/l and greater was the primary adverse effect of waterborne selenium on the juvenile bluegill. Bluegill exposed to 2.8 mg/l of waterborne Se for 30 d exhibited a significant reduction in condition factor (K), whereas dietary exposure of bluegill to 25 mg Se/kg for 30 d and 13 mg Se/kg or greater for 90 d elicited significant reductions in K. Mortality and swimming activity of bluegill were not affected in the dietary exposure. Net accumulation of Se from both water and diet was directly related to exposure concentration. Bioconcentration factors ranged from 5 to 7 for bluegill exposed to waterborne Se and from 0.5 to 1.0 for fish exposed to dietary Se. Results of these laboratory tests indicate that survival of bluegill may be impaired in natural waters with elevated Se concentrations.

Survival, sublethal responses, and tissue residues of Atlantic salmon exposed to acidic pH and aluminum

Abstract Early life stages of Atlantic salmon (Salmo salar) were continuously exposed to pHs ranging from 4.5 to 7.2 in one study, and to Al concentrations ranging from 33 to 264 μg/l at pH 5.5 in a second study. The tests were begun with eyed eggs and conducted until 60 d post-hatch. The exposure water contained about 3.0 mg/l calcium and was representative of acid-sensitive surface waters with low acid-neutralizing capacity. Hatching success, mortality, growth, behavior, and tissue residues of aluminum were determined during the tests. Egg hatching and the growth of larvae were reduced significantly at pH 4.5 and 5.0, and larval mortality increased at pH 4.5. Larval feeding and swimming behavior were impaired at pH 6.5 and lower. Hatching was not affected at pH 5.5 in the presence of Al; however, larvae exposed to 124 μg Al/l at pH 5.5 incurred significant increases in mortality. The inhibition of feeding observed among fish exposed to pH 5.5 was intensified at all concentrations of Al tested. At pH 5.5, reduced growth occurred among larvae exposed to 71 μg Al/l and higher. Concentrations of Al in whole-body tissue ranged from 3 μg/g for fish exposed to 33 μg Al/l to 96 μg/g for those exposed to 264 μg Al/l. At 60 d of exposure, bioconcentration factors ranged from 76 to 190 and were directly related to exposure concentration. Sublethal exposure of Atlantic salmon to acidic pH alone, and in combination with Al, may significantly reduce their fitness and may also play a significant role in recruitment failure in some acid-sensitive waters in the northeastern United States.

Toxicological and chemical screening of Antarctica sediments: Use of whole sediment toxicity tests, microtox, mutatox and semipermeable membrane devices (SPMDs)

Abstract Eight whole sediment samples from Antarctica (four from Winter Quarters Bay and four from McMurdo Sound) were toxicologically and chemically evaluated. Also, the influence of ultraviolet radiation on the toxicity and bioavailability of contaminants associated with the sediment samples was assessed. The evaluations were accomplished by use of a 10-day whole sediment test with Leptocheirus plumulosus, Microtox®, Mutatox® and semipermeable membrane devices (SPMDs). Winter Quarters Bay sediments contained about 250 ng g−1 (dry weight) total PCBs and 20 μg g−1 total PAHs. These sediments elicited toxicity in the Microtox test and avoidance and inhibited burrowing in the L. plumulosus test. The McMurdo Sound sediment samples contained only trace amounts of PCBs and no PAHs, and were less toxic in both the L. plumulosus and Microtox tests compared to the Winter Quarters Bay sediments. The sediments from McMurdo Sound apparently contained some unidentified substance which was photolytically modified to a more toxic form. The photolytic modification of sediment-associated contaminants, coupled with the polar ozone hole and increased incidence of ultraviolet radiation could significantly increase hazards to Antarctic marine life.

Sensitivity of brook trout to low pH, low and elevated aluminum concentrations during laboratory pulse exposures

Yolk-sac larvae of brook trout (Salvelinus fontinalis) were exposed to four sequential low pH and calcium (Ca) pulses, nominally ranging from pH 6.5 to 4.0 in 0.5 pH unit increments, with and without 300 mg/l aluminum (Al) in 28-day toxicity tests. Calcium concentrations during the pulses varied from 0.5 to 1.3 mg/1. Swim-up larvae that had begun to feed were exposed to a single pulse of the same pH and Ca concentrations with 300 mg/l Al. The larvae were allowed to recover for 120-h at circumneutral pH and Ca concentrations that varied from 2.1 to 3.3 mg/l after each pulse exposure. Effects of the pulse exposures on survival, growth, whole-body ion concentrations, and behavioral development were monitored. Mortality of larvae was significant in all low pH and Ca treatments with Al after the first pulse and after the first low pH and Ca pulse at pH 4.0. Growth was significantly reduced among larvae exposed to the low pH and Ca pulses at pH 4.0. In general, growth was most severely affected among larvae exposed to the low pH and Ca pulses with Al at pH 6.1 and lower. Relative to controls, the low pH and Ca pulse exposures with and without Al reduced whole-body Na+, Ca2+, K+, Mg2+ P, and Cl−, Wholebody Ca2+ was most severely reduced followed by Na+, K+, Cl−, P, and Mg2+. The pulse exposures also caused delayed development and significant reductions in swimming activity and feeding of the larvae. These results support field observations that cyclic pH and Ca depressions, and concurrent increases in Al concentrations may cause mortality and have other adverse effects on natural fish populations.

Influence of pH and aluminum on developing brook trout in a low calcium water

Eyed embryos of brook trout (Salvelinus fontinalis) were exposed to nominal pHs of 4.5, 5.5 and 7.5 with and without aluminum (300 microg liter(-1)) in extremely soft water (hardness <9mg liter (-1)) at 12 degrees C. Embryo mortality exceeded 80% at pH 4.5, averaged 15 to 18% in the pH 5.5 treatments and was less than 2% in the pH 7.5 treatments. Aluminum significantly reduced embryo mortality (85.3% vs 99.5%) at pH 4.5 but did not affect mortality at pH 5.5 or pH 7.5. Percent hatch and poor hatch were pH dependent and were not significantly influenced by aluminum. Brook trout larvae cumulative mortalities were 100% within 30 days at pH 4.5, with or without aluminum; 69% after 60 days at pH 5.5; 100% in 15 days at pH 5.5 with aluminum and 20% after 60 days at pH 7.5 with or without aluminum. Fish that survived the pH 5.5 treatment showed decreased growth and behavioral impairments compared to the controls (pH 7.5 without aluminum).

Influence of pH on the toxicity of aluminium and other inorganic contaminants to East Coast striped bass

The toxicity of Al and a mixture of inorganic contaminants to young striped bass Morone saxatilis in soft fresh water was demonstrated to be age- and pH-dependent. Toxicity of the contaminants was increased with decreases of pH of the test waters. The interaction between low pH from acid deposition and inorganic contaminants should be considered as a possible factor contributing to the decline in abundance of east coast striped bass.

Toxicity of contaminated sediments in dilution series with control sediments

Abstract The use of dilutions has been the foundation of our approach for assessing contaminated water, and accordingly, it may be important to establish similar or parallel approaches for sediment dilutions. Test organism responses to dilution gradients can identify the degree of necessary sediment alteration to reduce the toxicity. Using whole sediment dilutions to represent the complex interactions of in situ sediments can identify the toxicity, but the selection of the appropriate diluent for the contaminated sediment may affect the results and conclusions drawn. Contaminated whole sediments were examined to evaluate the toxicity of dilutions of sediments with a diversity of test organisms. Dilutions of the contaminated sediments were prepared with differing diluents that varied in organic carbon content, particle size distribution, and volatile solids. Studies were conducted using four macroinvertebrates and a vascular, rooted plant. Responses by some test organisms followed a sigmoidal dose-response curve, but others followed a U-shaped curve. Initial dilutions reduced toxicity as expected, but further dilution resulted in an increase in toxicity. The type of diluent used was an important factor in assessing the sediment toxicity, because the control soil reduced toxicity more effectively than sand as a diluent of the same sediment. Using sediment chemical and physical characteristics as an indicator of sediment dilution may not be as useful as chemical analysis of contaminants, but warrants further investigation.

Toxicity of the organophosphorus defoliant def to rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus)

Abstract Ninety-day partial life cycle toxicity tests were conducted to determine the effects of the organophosphorus defoliant S , S , S -tributyl phosphorotrithioate (DEF), on rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus) . Exposure concentrations were 0, 0.76, 1.2, 1.7, 2.7, 3.6, 6.5, and 9.5 μg/l for rainbow trout and 0, 0.77, 2.0, 4.8, 10.0, and 19.6 μg/l for channel catfish. In rainbow trout growth was reduced by DEF concentrations ≥ 1.2 and survival by concentrations ≥ 3.6 μg /l; growth and survival of channel catfish were reduced by DEF concentrations ≥ 4.8 and 19.6 μg /l, respectively. DEF adversely affected vertebral biochemical composition and mechanical properties of both species. DEF was not highly accumulative in the tissues of either species and was eliminated rapidly when the fish were transferred to contaminant-free water. The determination of safe environmental concentrations of DEF depends partly on the species tested and the biological response measured. Application factors classically used to estimate safe environmental concentrations of contaminants may not be applicable to some of the new-generation organophosphate compounds in relation to cold-water species such as rainbow trout.

Chronic toxicity of an environmental contaminant mixture to young (or larval) striped bass

Larvae of striped bass (Morone saxatilis (Walbaum)) were exposed to a mixture of organic and inorganic contaminants in fresh well water and 2 g L−1 saline water for 30 days and in 5 g L−1 saline water for 90 days.Environmental concentrations (ECs) of organic and inorganic chemicals were estimated for the Chesapeake Bay area. Striped bass were exposed to the EC, 0.25 EC, 0.5 EC, 2 EC, 4 EC, and a solvent control to simulate potential conditions in their spawning and nursery habitats of the Chesapeake Bay. The sensitivities of striped bass as determined by survival depended on the characteristics of the exposure water. Larvae exposed in fresh well water were the most susceptible to the contaminant mixture; the 2 and 4 EC treatments caused significant (P:5 0.05) mortality within 30 days. In the 2 g L−1 salinity water, the 4 EC treatment caused significant mortality after 30 days of exposure. Larvae exposed to the contaminant mixture for 90 days in the 5 g L−1 saline water incurred significant mortality in the 2 and 4 EC treatments. We concluded that the age of the larvae, concentration of the contaminants, and salinity of the environment must be considered in evaluating the influence of environmental contaminants on the decline of striped bass along the east coast.