Effects of Copper Sulfate on Typha latifolia Seed Germination and Early Seedling Growth in Aqueous and Sediment Exposures

The vascular macrophyte Typha latifolia Linnaeus (common cattail) may be a sentinel for evaluating potential phytotoxicity to rooted aquatic macrophytes in aquatic systems. To further evaluate the potential utility of this species, T. latifolia seed germination, shoot growth, and root elongation were measured in 7-day aqueous exposures using mean measured aqueous copper concentrations of 10.0, 23, 41, 62, 174, and 402 μg Cu/L, which were ≥ 62% of nominal concentrations. Seed germination and seedling shoot growth were not significantly affected by any of these copper concentrations as compared to controls. Mean measured no-observed-effect-concentration (NOEC) and lowest-observed-effect-concentration (LOEC) for root elongation were 18.6 μg Cu/L and 35.0 μg Cu/L, respectively. Seven-day sediment tests were conducted by amending uncontaminated sediments with copper sulfate to mean measured concentrations of 7.9, 17.1, 21.0, 51.2, 89.5, and 173.5 mg Cu/kg, which were ≥ 84% of nominal concentrations. Seed germination was not significantly different from controls. Mean measured NOEC and LOEC values for seedling shoot growth were 89.5 mg Cu/kg and 173.5 mg Cu/kg, respectively, and mean measured NOEC and LOEC values for root growth were 14.0 mg Cu/kg and 19.7 mg Cu/kg, respectively. These results demonstrate that T. latifolia early seedling growth can be utilized for assessing aqueous and sediment toxicity of copper. Received: 21 March 2000/Accepted: 28 August 2000     

Toxicity of Metals to the Bivalve Tellina deltoidalis and Relationships Between Metal Bioaccumulation and Metal Partitioning Between Seawater and Marine Sediments

The Australian benthic bivalve Tellina deltoidalis tolerates a wide range of sediment and water conditions, is easy to handle in the laboratory, and is a useful species for undertaking whole-sediment toxicity tests. The sensitivity of T. deltoidalis to metals was investigated in 10-day metal-spiked sediment exposures for Cd, Cu, Ni, Pb, and Zn and in water-only exposures for Cu and Zn. The survival of T. deltoidalis in 10-day exposures to metal-spiked sediments was 88–100% for Cd, Ni, Pb, and Zn concentrations of 75, 420, 1,000, and 4,000 mg/kg, respectively. The 4-day LC₅₀s for dissolved Cu and Zn were 0.18 and 13 mg/L, respectively. The 8-day LC₅₀ for Cu was 31 (24–34) μg/L. Cu and Zn concentrations in the tissues of T. deltoidalis increase linearly with increasing dissolved exposure concentration. In the Cu-spiked sediment and water exposures, the survival was negatively correlated with the Cu concentration in both the overlying water and in the tissues of T. deltoidalis. In contrast, particulate Cu concentrations were found to be a poor predictor of Cu bioaccumulation and toxicity for Cu-spiked sediments.     

Toxicity of Select Beta Adrenergic Receptor-Blocking Pharmaceuticals (B-Blockers) on Aquatic Organisms

One class of pharmaceutical compounds identified in U.S. and European waters are the B-adrenergic receptor blocking compounds (B-blockers). However, little information is available on the potential aquatic toxicity of these compounds. Therefore, Hyalella azteca, Daphnia magna, Ceriodaphnia dubia, and Oryias latipes (Japanese medaka) were exposed to metoprolol, nadolol, and propranolol to determine potential toxicity. Average 48-h LC₅₀ for propranolol to H. azteca was 29.8 mg/L. The no-observed-effects concentration (NOEC) and lowest-observed-effects concentration (LOEC) for propranolol affecting reproduction of H. azteca were 0.001 and 0.1 mg/L, respectively. The average propranolol and metoprolol 48-h LC₅₀s for D. magna were 1.6 and 63.9 mg/L, respectively. C. dubia 48-h LC₅₀s were 0.85 and 8.8 mg/L for propranolol and metoprolol, respectively. The NOEC and LOEC of propranolol affecting reproduction in C. dubia were 0.125 and 0.25 mg/L, respectively. In O. latipes, the propranolol 48-h LC₅₀ was 24.3 mg/L. Medaka growth was decreased at 0.5 mg/L propranolol. A 2-week medaka reproductive study indicated significant changes in plasma steroid levels; however, no changes in the average number of eggs produced or number of viable eggs which hatched was observed. In a 4-week follow-up propranolol exposure, the total number of eggs produced by medaka and the number of viable eggs that hatched were decreased at concentrations as low as 0.5 μg/L. Based on this study and the expected aqueous environmental exposure levels, adverse effects of propranolol to invertebrate populations is unlikely; however, further reproductive studies are need to elucidate the risk to teleosts. Received: 14 August 2001/Accepted: 4 March 2002     

Animal Health Problems Attributed to Environmental Contamination in Lake Nakuru National Park,Kenya: A Case Study on Heavy Metal Poisoning in the Waterbuck <Emphasis Type="Italic">Kobus ellipsiprymnus defassa</Emphasis> (Ruppel 1835)

A study was conducted in which samples of soil, forage, as well as serum, bone, kidney, and liver of waterbuck were collected from Lake Nakuru National Park. The objective was to determine the ecosystem health status in order to establish the causes of animal health problems previously recorded in some sections of the Park. Trace element analysis in serum indicated occurrence of copper (Cu) deficiency in the north and eastern sections of the Park where mean values were marginal (range: 0.36–0.81, mean: 0.62 mg/l) compared to concentrations recorded in the western part of the Park (range: 0.69–1.48, mean: 1.22 mg/l). Bone analysis on dry matter basis (DM) indicated higher (p < 0.01) levels of cadmium (Cd, 0.437 mg/kg), fluoride (F, 3178 mg/kg), and lead (Pb, 20.62 mg/kg) in animals from the east compared to those from the west (0.002, 1492, 4.87 mg/kg, respectively), suggesting heavy exposure. In addition, samples from the east had much lower than normal calcium (Ca)-to-phosphorus (P) ratios (mean: 1.9:1) compared to those recorded in the west (2.2:1), suggesting poor bone mineralization. There was a higher concentration of Cd in the kidney (16.24 mg/kg, p < 0.05) and Pb in the liver (58.3 mg/kg, p < 0.01) in animals from the east compared to those in the west (12.92 and 36.2 mg/kg, respectively), but the converse was true of Cu. The liver Cu status was better in animals from the west with, concentrations (mean: 21.7 mg/kg) being about twice those recorded in the east (11.9 mg/kg DM). Forage analysis revealed prospects of Ca, P, and Cu deficiencies in the entire Park. However, in the northeastern section of the Park (measuring 50 ha) where waterbuck residence times are high, forage concentrations of Cd (0.31 mg/kg DM), molybdenum (Mo, 7.20 mg/kg DM), Pb (2.88 mg/kg DM), and zinc (Zn, 126 mg/kg DM) were an order of magnitude greater (p < 0.01) than the levels recorded in the rest of the Park (ranges: 0.133–0.165, 3.69–5.61, 0.485–0.621, 11.6–17.4 mg/kg DM, respectively). These disparities were attributed to a higher soil concentration of Cd (2.77 mg/kg DM), Pb (85.1 mg/k DM) and Zn (1414 mg/kg DM) in this section compared to the rest of the Park (ranges: 0.10–0.15, 5.02–6.26, 1.49–5.44 mg/kg DM, respectively), and strongly suggest heavy metal contamination as the source of animal health problems in the Park.     

Acute and Chronic Toxicity of Copper to the Euryhaline Rotifer, <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> (“L” Strain)

This article presents data from original research, intended for the use in the development of copper (Cu) criteria for the protection of estuarine and marine organisms and their uses in the United States. Two 48-h static-acute toxicity tests—one with and one without added food—and a 96-h static multigeneration life-cycle test (P1–F2 generations) were performed concurrently using the euryhaline rotifer Brachionus plicatilis (“L” strain) to develop a Cu acute-to-chronic ratio (ACR) for this species. Tests were performed at 15 g/L salinity, at 25°C, and the exposure concentrations of dissolved Cu were verified. Supplemental chemical analyses were performed and reported for the development of a Cu–saltwater biotic ligand model (BLM). Supplemental analyses included alkalinity, calcium, chloride, dissolved organic carbon (DOC), hardness, magnesium, potassium, sodium, and temperature. The acute toxicity test measurement end points were the dissolved Cu median lethal concentration (LC₅₀) values based on rotifer survival. The chronic measurement end points were the dissolved Cu no-observed-effect concentration (NOEC), lowest-observed-effect concentration (LOEC), EC₂₅, EC₂₀, and EC₁₀ based on the intrinsic rate of rotifer population increase (r). The 48-h LC_50Fed, 48-h LC_50Unfed, 96-h NOEC, 96-h LOEC, EC₂₅, EC₂₀, and EC₁₀ were 20.8, 13.4, 6.1, 10.3, 11.7, 10.9, and 8.8 μg Cu/L, respectively. The ACRs were calculated as ratios of each 48-h LC₅₀ value [fed and unfed) and each of the 96-h chronic values (ChV; geometric mean of NOEC and LOEC)], EC₁₀, EC₂₀, and EC₂₅. The ACRs ranged from 1.15 to 2.63.     

Enantioselective Chronic Toxicity of Fipronil to <Emphasis Type="Italic">Ceriodaphnia dubia</Emphasis>

Fipronil is a phenylpyrazole pesticide that has greatly increased in popularity in recent years. As a chiral molecule, fipronil is released into the environment as a 1:1 mixture (called a racemate) of its two enantiomers. Previous toxicity work has indicated that the enantiomers of fipronil exhibit significantly different levels of acute toxicity to the nontarget organism Ceriodaphnia dubia. In this work we examine the chronic effects of the pure enantiomers and racemate on the survival, development, mobility, and reproduction of C. dubia adults and the survival and mobility of their offspring. Based on 8-day trials, the (+) enantiomer of fipronil showed a significantly greater reduction in the number of offspring (LOEC = 2 μg/L) than either the racemate (LOEC = 15 μg/L) or the (−) enantiomer (LOEC = 30 μg/L). The (+) enantiomer was also shown to be significantly more toxic to neonates born during the course of the experiment (LC50₂₄ = 18.1 μg/L, LC50₄₈ = 10.3 μg/L) than the racemate (LC50₂₄ = 33.3 μg/L, LC50₄₈ = 30.3 μg/L), but only after 48 h. Both the (+) enantiomer and the racemate were significantly more toxic to C. dubia than the (−) enantiomer (LC50₂₄ = 65.2 μg/L, LC50₄₈ = 50.1 μg/L) at both time points. Qualitative mobility data followed a similar trend, with the (+) enantiomer causing greater impairment in mobility at low concentrations. These data imply that the (−) enantiomer has less impact on the reproductive success of C. dubia than either the (+) enantiomer or the racemate. Enantiomerically pure or enriched formulations of (−) fipronil may reduce impacts to the nontarget organism C. dubia.     

Effects of Soil Copper on Black Bindweed (Fallopia convolvulus) in the Laboratory and in the Field

The present study aims to identify factors of importance to the extrapolation from laboratory toxicity test to field effects using copper and black bindweed as a model. In the laboratory the influence of Cu on seed germination and seedling survival was studied in both soil spiked with Cu in the laboratory and soil collected at a Cu-polluted site. Maternal effects were also studied. We found that seeds from Cu-stressed plants germinated more readily after a short, cold storage than control seeds, but no differences were found after a longer storage. The low germination of control seeds compared to maternal treated seeds could not be attributed to differences in thickness of the seed coat. Germination was slightly stimulated at 232 mg Cu kg⁻¹. At the highest Cu level (i.e. 1,330 mg Cu kg⁻¹) only 5% of the seeds germinated. Mortality of the seedlings increased with increasing Cu concentration reaching 40% at 391 mg Cu kg⁻¹. At higher concentrations mortality decreased. Germination was not affected in laboratory tests with soil from a Cu-polluted site, but the biomass of the plants decreased with increasing Cu concentration. The distribution of the plants on a Cu-polluted site was registered in relation to soil Cu concentration. Cu was analyzed using three different extractors, i.e. HNO₃, CaCl₂, and DTPA. The distribution of the plant in the field was predicted from calculated lifetime effect of a given Cu soil concentration based on the laboratory tests. The results revealed that growth is more sensitive in the field than should be expected from laboratory tests due to several stressors in the former situation. Bioavailability was lower in the field soil but this was counteracted by the increased effect. Incorporating bioavailability in the prediction of field effects thus reduced the fit of the model and bioavailability measures could not be further evaluated. Received: 28 December 1996/Accepted: 3 January 1998     

Assessment of Diazinon Toxicity in Sediment and Water of Constructed Wetlands Using Deployed <Emphasis Type="Italic">Corbicula fluminea</Emphasis> and Laboratory Testing

Constructed wetlands for mitigation of nonpoint agricultural runoff have been assessed for their ability to decrease potential toxicity from associated contaminants. After a simulated runoff event, constructed wetlands positioned in series were used to measure the effects of the organophosphate insecticide diazinon. Water, sediment, and plant samples from five sites were analyzed for diazinon concentrations from 0.5 hours to 26 days; peak concentrations were measured in sediment after 0.5 hours (268.7 μg/kg) and in water and plant tissue after 3 hours (121.71 μg/L and 300.7 μg/kg, respectively). Cholinesterase activity and changes in shell growth were measured from Corbicula fluminea deployed at corresponding sites. Water collected after 9 hours from all wetland sites contained diazinon concentrations sufficient to cause toxicity to Ceriodaphnia dubia, but not to Pimephales promelas. C. dubia survival was decreased in water sampled through 7 days from the site nearest runoff introduction, whereas C. fluminea deployed at this same site experienced 100% mortality after 26 days. Clams from lower sites survived wetland conditions, but growth and ChE activity were significantly decreased lower than that of clams from a control site. C. dubia exposed to water from these sites continued to have decreased survival throughout the 26-day sampling. Sediment sampled from 48 hours through 14 days at the lowest wetland site decreased the laboratory survival of Chironomus dilutus, and sediment from upper sites elicited an effect only on day 26. Although wetland concentrations of aqueous diazinon were decreased lower than toxic thresholds after 26 days, decreased ChE activity in deployed clams provided evidence of residual diazinon effects to deployed organisms. All programs and services of the United States Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, marital status, or handicap. Mention of a pesticide in this article does not constitute a recommendation under the Federal Insecticide, Fungicide, and Rodenticide Act as amended. Names of commercial products are included for the benefit of the reader and do not imply endorsement or preferential treatment by the United States Department of Agriculture.     

The Concentrations and Bioconcentration Factors of Copper and Zinc in Edible Mushrooms

Copper and zinc contents have been determined in up to 28 species of edible mushrooms from different sites in the province of Lugo (NW Spain). Two hundred thirty-eight collected samples were analyzed by an anodic stripping voltammetric technique using a drop mercury as the working electrode. The results showed that the element concentrations were species-dependent, and the highest metal levels corresponded to the following species: Calvatia utriformis (235.5 mg Cu/kg), Macrolepiota procera (217.8 mg Cu/kg), and Agaricus macrosporus (217.7 mg Cu/kg) and Calvatia utriformis (265.8 mg Zn/kg), Lactarius delicious (231.0 mg Zn/kg), and Agaricus macrosporus (221.3 mg Zn/kg) for Cu and Zn, respectively. All mushroom species bioaccumulated copper and zinc. Nevertheless, some individual samples of the species, such as Hydnum repandum, Cantharellus cibarius, and Coprinus comatus, were bioexclusors (BCF < 1). The hymenophore in mushrooms showed higher mean metal levels than the rest of the fruit bodies, with statistically significant differences. The copper and zinc concentrations were compared to literature data and levels set by legislation. It can be concluded that the consumption of these mushrooms cannot be considered a toxicological risk, and they provide an important nutritional requirement to the diet. Received: 9 April 2002/Accepted: 6 August 2002     

Assessing Caffeine as an Emerging Environmental Concern Using Conventional Approaches

Organic wastewater contaminants, including pharmaceuticals, caffeine, and nicotine, have received increased scrutiny because of their detection in water bodies receiving wastewater discharge. Despite recent measurement in United States streams, caffeine’s effect on freshwater organisms is not well documented. The present study measured caffeine’s lethal and sublethal effects on the freshwater species, Ceriodaphnia dubia, Pimephales promelas, and Chironomus dilutus. These organisms, which are used in standard testing or effluent monitoring, were exposed to aqueous caffeine solutions under static exposure for 48 hours and daily renewed static exposure for 7 days. Averaged responses of 48-hour acute end points indicated that C. dubia was more sensitive to caffeine exposures (LC₅₀ = 60 mg/L) than either P. promelas (LC₅₀ = 100 mg/L) or C. dilutus (LC₅₀ = 1,230 mg/L). Exposure-response slopes confirmed these findings (3% mortality/mg/L for C. dubia; 0.5% mortality/mg/L for P. promelas; and 0.07% mortality/mg/L for C. dilutus). Comparative 7-day responses between C. dubia and P. promelas (LC₅₀ = 46 and 55 mg/L, respectively) were more similar than the broad range of acute values. Sublethal effects measured for caffeine exposure included impaired C. dubia reproduction (IC₅₀ = 44 mg/L) and inhibited P. promelas growth (IC₅₀ = 71 mg/L). According to the results of this study, combined with earlier studies reporting environmental concentrations and product half-lives, caffeine should pose negligible risk for most aquatic vertebrate and invertebrate organisms.     

Octamethylcyclotetrasiloxane in aquatic sediments: Toxicity and risk assessment

The toxicity of octamethylcyclotetrasiloxane (OMCTS) to the midge Chironomus tentans was examined in a series of aqueous and sediment exposures. Midge larvae were exposed for 14 days to five concentrations of radiolabeled [¹⁴C]OMCTS in each of three sediments (low, medium, and high organic carbon content). Additional tests were conducted with a water-only exposure. Results indicate the lowest 14-day no observed effect concentrations (NOEC) to be 65, 120, and 54 mg/kg for the low, medium, and high organic carbon sediments, respectively. For the water-only exposure, the 14-day NOEC was > 15 μg/liter. These results were used in the preparation of a risk assessment for OMCTS which took into consideration the physicochemical and environmental fate properties of the compound, as well as actual field monitoring and worst-case modeling results for assessment of exposure. Available evidence suggests that sediment concentrations of OMCTS do not present a risk to sediment-associated organisms. For 95% of sediment samples, data indicate that the margins of safety would be greater than 400 and potentially over 1000. Worst-case margins of safety were greater than 150.     

Embryo-Larval Toxicity Tests with the African Catfish (Clarias gariepinus): Comparative Sensitivity of Endpoints

Embryo-larval toxicity tests with the African catfish (Clarias gariepinus) were performed to assess the comparative sensitivity of different endpoints. Measured test responses included embryo and larval survival, hatching, morphological development, and larval growth. Chromium, cadmium, copper, sodium pentachlorphenol (NaPCP), and malathion were used as model toxicants. Hatching was not affected by any of the chemicals tested, and embryo survival was only affected by chromium at ≥ 36 mg/L. The growth of larvae was significantly reduced at ≥ 11 mg/L Cr, ≥ 0.63 mg/L Cu, ≥ 0.03 mg/L NaPCP, and ≥ 1.25 mg/L malathion. Morphological development of C. gariepinus was affected by all of the toxicants tested. Different types of morphological aberrations were observed, i.e., reduction of pigmentation in fish exposed to cadmium and copper, yolk sac edema in fish exposed to NaPCP and malathion, and deformation of the notochord in fish exposed to chromium and malathion. The sensitivity of the endpoints measured can be summarized as follows: growth > abnormality > larval survival > embryo survival > hatching. Received: 27 April 2001/Accepted: 26 August 2001     

Assessment of the State of the Gibel Carp <Emphasis Type="Italic">Carassius auratus gibelio</Emphasis> in the Amur River Basin: Heavy-Metal and Arsenic Concentrations and Histopathology of Internal Organs

This study describes the concentrations of heavy metals and arsenic (As) and the basic histopathological changes in the internal organs of gibel carp Carassius auratus gibelio from five sites of the Amur River basin. Gibel carp from Sindinskaya Passage had the highest liver concentrations of zinc (Zn) (31.95 ± 13.443), copper (Cu) (12.52 ± 5.746), manganese (9.22 ± 8.121), and cadmium (0.37 ± 0.660 mg/kg wet weight [ww]) compared with fish captured from the Bol’shoi Ussuriiskii Island area and Kadi Lake; however, concentrations of nickel (0.22 ± 0.156 mg/kg ww) were not significantly different, and concentrations of lead (0.19 ± 0.121 mg/kg ww) were higher than those in fish from Kadi Lake. Mean concentrations of metals and As in muscles were lower than Russia’s recommended limits for food products; however, concentrations of Cu, Zn, and Hg in individual fish were greater than the limit. Kidney disease was detected in 100% of sampled carp. Kidney disease was characterized by the formation of numerous granulomas in kidney tissues between the renal tubules. The degree of granulomatosis varied among sites. Granulomatous kidney disease in gibel carp is widespread in many reservoirs of the lower Amur River basin. The following histopathological changes were detected in liver: vacuolization of hepatocytes, hypertrophy of multiple hepatocytes, binuclearity, presence of numerous irregularly shaped nuclei in hepatocytes, karyopyknosis, diffuse necrosis of hepatocytes (in some cases focal), and edema. Necrotic changes in hepatocytes, which are important indices of the toxic effect of pollutants, were found in the majority of investigated carp from the lower Amur River basin. Some fish had simultaneous pathological alterations in multiple organs.     

Acute and chronic effects of four commercial herbicide formulations on Ceriodaphnia dubia

Toxicity tests with Ceriodaphnia dubia were conducted to determine acute (48 h) and chronic (7-day survival and reproduction) effects of four commonly used herbicide formulations. The 48-h LC50s in decreasing order of toxicity were 14.36 mg/L (Micro-Tech^®), 15.93 mg/L (Bicep^®), 32.99 mg/L (Extrazine^®), and 35.36 mg/L (Lexone^®). Reduced reproduction was detected at concentrations below 48-h LC50s for three of the formulations. The 7-day chronic values (ChV) based on reproduction were 17.68 mg/L (Micro-Tech^®), 8.84 mg/L (Bicep^®), 17.68 mg/L (Extrazine^®), and 8.84 mg/L (Lexone^®). The acute-to-chronic ratios (ACRs) for Micro-Tech^® (0.81), Bicep^® (1.80), Extrazine^® (1.86), and Lexone^® (4.00) indicate a relatively narrow range between acute and chronic sensitivity in daphnids. A comparison of these response data to environmental concentrations suggests these herbicides are not likely to directly impact invertebrates. Potential impacts on plants and human health should be of primary ecological and regulatory concern.     

Using a Sediment Quality Triad Approach to Evaluate Benthic Toxicity in the Lower Hackensack River,New Jersey

A Sediment Quality Triad (SQT) study consisting of chemical characterization in sediment, sediment toxicity and bioaccumulation testing, and benthic community assessments was performed in the Lower Hackensack River, New Jersey. Chemistry data in sediment and porewater were evaluated based on the equilibrium partitioning approach and other published information to investigate the potential for chemical effects on benthic organisms and communities. Relationships were supported by laboratory toxicity and bioaccumulation experiments to characterize chemical effects and bioavailability. Benthic community results were evaluated using a regional, multimetric benthic index of biotic integrity and four heterogeneity indices. Evidence of slight benthic community impairment was observed in five of nine sediment sample stations. Severe lethal toxicity to amphipods (Leptocheirus plumulosus) occurred in four of these five stations. Although elevated total chromium concentrations in sediment (as high as 1900 mg/kg) were the rationale for conducting the investigation, toxicity was strongly associated with concentrations of polycyclic aromatic hydrocarbons (PAHs) rather than total chromium. PAH toxic units (ΣPAH TU) in sediment and ΣPAH concentrations in laboratory organisms from the bioaccumulation experiment showed a clear dose–response relationship with toxicity, with 0% survival observed in sediments in which ΣPAH TU > 1–2 and ΣPAH concentrations in Macoma nasuta were >2 μmol/g, lipid weight. Metals detected in sediment and porewater, with the possible exception of copper, did not correlate with either toxicity or levels in tissue, likely because acid-volatile sulfide levels exceeded concentrations of simultaneous extracted metals at all sample locations. The study reinforces the value of using multiple lines of evidence approaches such as the SQT and the importance of augmenting chemical and biological analyses with modeling and/or other approaches to evaluate chemical bioavailability and toxicity of sediments.     

Effects of Sublethal Chronic Copper Exposure on the Growth and Reproductive Success of the Florida Apple Snail (Pomacea paludosa)

Florida apple snails (Pomacea paludosa) were exposed to three concentrations of copper (Cu), in water (8 μg/L, 16 μg/L, 24 μg/L), for one generation to examine uptake and the effects on survival, growth, and reproduction of the F₀ generation and survival, growth, and whole body Cu of the F₁ generation. During a 9-month Cu exposure, apple snails exposed to 8–16 μg/L Cu had high Cu accumulation (whole body, foot, viscera, and shell) and significantly reduced clutch production (8–16 μg/L) and egg hatching (16 μg/L). Apple snails exposed to the 24 μg/L Cu had low survival and the treatment was therefore terminated. Concentrations of minerals (Na⁺, K⁺, Mg²⁺, Ca²⁺) in tissues were maintained regardless of Cu exposure, but the distribution of Cu in the body of snails differed, depending on exposure concentrations. Higher exposure concentrations resulted in a greater percentage of Cu accumulated in the viscera of the snail. Copper exposure to the F₀ generation did not affect the survival, growth, or whole body Cu concentrations in the F₁ generation. These finding are significant, given the importance of the Florida apple snail in the Everglades food chain. Changes in the abundance of apple snail populations, as a result of Cu exposure, could ultimately affect foraging success of predators.     

Selenium, Cadmium, Copper, and Zinc Concentrations in Sediments and Mullet (Mugil cephalus) from the Southern Basin of Lake Macquarie, NSW, Australia

Selenium, cadmium, copper, and zinc concentrations were measured in sediments and the tissues of mullet (Mugil cephalus) collected from the southern basin of Lake Macquarie, NSW, Australia. Trace metals in surficial sediments are enriched in trace metals relative to background concentrations (selenium, 3–19; cadmium, 14–42; copper, 1.5–3.6; zinc, 0.77–2.2 times background). Selenium, cadmium, and copper in Lake Macquarie mullet tissues are elevated compared to those in mullet collected from the Clyde River estuary, a relatively pristine location. Selenium and copper concentrations are also elevated compared to those reported in mullet tissues from other nonpolluted coastal environments. Zinc concentrations in Lake Macquarie mullet muscle tissues are significantly higher than those in muscle tissues of mullet from the Clyde River estuary, but mullet from both locations have similar zinc concentrations in other tissues. These results show that contamination of sediment with trace metals has resulted in elevated trace metals in the benthic feeding fish M. cephalus. Little of the variation of trace metal concentrations between fish was explained by variation in mass. Selenium concentrations in mullet are of concern in muscle tissues as they are above recommended acceptable limits for safe human consumption, while concentrations in tissues are at levels that may effect fish growth, reproduction, and survival. Copper concentrations in mullet tissues are also at levels that may reduce fish growth. Received: 11 September 1999/Accepted: 9 July 2000     

Effects of Copper in Flooded Florida Agricultural Soils on <Emphasis Type="Italic">Hyalella azteca</Emphasis>

This study examined the uptake and effects of copper (Cu) from flooded agricultural soils to epibenthic amphipods (Hyalella azteca) using 10-day sediment toxicity tests. Soils were collected from 10 citrus agricultural sites in South Florida. One sediment toxicity test was conducted with one flooding of the 10 soils, and based on the results of this test a second sediment toxicity test was conducted with 4 of the soils, after four 14-day flooding and four 14-day drying intervals over 4 months. Sediment toxicity tests were conducted under flow-through conditions using U.S. EPA methodology. Effects on survival, dry weight, and whole-body Cu concentrations of H. azteca were determined. Cu concentrations in overlying water and sediment of both sediment toxicity tests exceeded regulatory criteria for aquatic organisms. Although survival of H. azteca was not consistently affected from the first to the second sediment toxicity tests, dry weight was consistently reduced and related to Cu concentrations in soil, overlying water, and pore water. Furthermore, whole-body tissue Cu concentrations were significantly higher in H. azteca in all 10 soil-water treatments in the first sediment toxicity test and in all 4 soil-water treatments in the second sediment toxicity test compared to controls. Whole-body tissue concentrations and effects on dry weight were related to Cu exposures in soil, overlying water, and pore water. In these managed soil-water systems, small fish consuming H. azteca with high concentrations of Cu may be at risk.     

Seasonal Variations in the Concentrations of Metals in Crassostrea corteziensis from Sonora, México

This study examines seasonal variations in the concentrations of Cd, Cu, Pb, and Hg in experimentally cultured Crassostrea corteziensis, an oyster species known to have high resistance to physical and chemical stressors. The highest levels of Cd (4.92 mg/kg), Cu (3.45 mg/kg), and Pb (0.67 mg/kg) were detected in oyster samples collected during the summer, while Hg concentrations were similar (0.03 to 0.04 mg/kg) throughout all seasons. Results indicate that except for Cd, Crassostrea corteziensis accumulates metals to levels below those recommended by the US. FDA and the Mexican government. For Cd, its concentration correlates more strongly with the temperature of the oyster’s environment rather than to the oyster growth cycle.     

Trace Metal Content in Mussels, Perna viridis L., Obtained from Selected Seafood Markets in a Metropolitan City

Mussels, Perna viridis L., obtained from three selected seafood markets in Metro Manila, were tested for metal content including cadmium, copper, lead, and zinc through atomic absorption spectrophotometry. Water samples from Bacoor Bay, Cavite, which supplies mussels to the market, were likewise subjected to similar metal analyses. Of the metals analyzed in the soft tissues of mussels, only copper and lead with highest obtained values of 10.4 mg/kg and 2.3 mg/kg, respectively exceeded the PEMSEA guideline for safe human consumption. Water samples collected from the harvest sites in Bacoor Bay showed high concentrations of cadmium (0.023 mg/L) and lead (0.25 mg/L) that exceeded the standards of DENR, ASEAN, and US EPA. Zinc, though detected in relatively high concentrations in both water (0.03 mg/L) and soft tissues (12.16–14.43 mg/kg) of mussels remained below the criteria set by the above-mentioned agencies. Overall, the present study indicates that mussels being sold in selected Metro Manila seafood markets were contaminated with metals, notably Cu and Pb, at concentrations that are unsafe for human consumption and thus, represents a health risk.