Metals and pesticide levels found in fish taken from Vancouver Lake: memorandum to Steve O'Brien, dated May 19, 1977

The Vancouver Lake Pilot Dredge Study revealed concentrations of certain chemicals which could be of concern: the metals copper, zinc and mercury and the pesticides lindane and aldrin were found in significant amounts. (PDF contains 1 page)

Trace metals -- a potential threat to our fishing industry

Trace metals constitute a major form of water pollutant that can adversely affect fish production. The potentially toxic metals have been identified as lead, zinc, copper, arsenic, antimony, mercury beryllium, barium, cadmium, chromium, nickel, selenium among others. Preliminary laboratory studies have been directed to the determination of traces of lead in the aquatic biota and its toxicity. There are indications that the levels reported in effluents from some of the industries may be above the tolerant limits of local fish species and organisms that make up their food. Metal pollution could become a serious problem to freshwater fisheries in the future as a result of increasing urbanization and industrialization, unless efforts are made to prevent it

Evaluation of the body burdens of heavy metals in five commercially important fishes from different locations in Kainji Lake

The level and distribution of some heavy metals viz Cadmium, Lead, Copper Zinc, and Cobalt in five commercially important fishes, water and sediments at three different locations in Kainj Lake were determined using standard methods. The results show that the ranges of heavy metals mu g/g in fishes in Dam site Laotian are: Cd (0.05~c0.01-20~c01), (Pb(ND-1.12 plus or minus )1), Cu (0.81~c25-2.93~c06), Zn (20.89 arrow right .15-36.78~c2.97), Co(0.08~c01-0.27~c02); in cover Dam, the ranges are Cd (0.04~c02-0.16~c0.2), Pb (nd-02~c01), Cu(0.75~c05-2.61~c13), Zn(15.70~c1.55-32.23~c2.70), Co(0.04~c02-0.25~c0.01) and in Yuna they are Cd (0.05~c01-0.14~c02), Pb (nd-0.32~c01), Cu (0.23~c07-2.70~c05), Zn(15.50 plus or minus `.35-25.62~c2.47), Co(0.07~c02-23~c0.01). The metals concentration (mg/l) in the water sample from Dam site, cover dam and Yuna respectively are Cd(0.007~c001,. 004~c001 and 0.005~001), Pb(013~c001, ND and ND), Cu(.055~c008.030~c007, 05 plus or minus .010), Zn(0.13~c01, 0.060 plus or minus .0055) and Co (.026 plus or minus .022 plus or minus .004, .024 plus or minus .004), while the metals concentration ( mu g/g) in sediments sample from Dam site, cover dam and Yuna are respectively Cd(.05 plus or minus .01, .02 plus or minus .01), Pb(16.00~c1.00, ND and 9.33~c1.01), Cu(24.00~c1.34, 4.26 plus or minus .91 and 11.08~c1.32), Zn(42.00~c1.00, 35~c10 and 38.00 plus or minus .45), Co(15.00~c1.17, 8.69~c1.21 and 10.91~c44). The concentrations of the tested heavy metals are within the acceptable standards of WHO (1987a)

Flowering in British Lemna: A rare, cyclic or simply overlooked phenomenon?

It is largely presumed that reproduction in British Lemna, as in other British Lemnaceae, is almost entirely asexual, with new daughter fronds being produced from the side pouches of older mother fronds. Sexual reproduction is considered to be a rather rare event or even absent and because of this rarity the sexual features of Lemna, such as anthers and fruit, are often considered to be of little taxonomic value. It was with some surprise, therefore, that widespread flowering was observed in all British Lemna during the summer of 1995. Initial observations in Shropshire during June recorded flowers in minor and trisulca, with fruit production in trisulca. L.gibba, minor and minuta were noted as being in flower on several occasions in Kent, during July and August, probably fruit production occurring in both species. To what extent these events are truly representative of the sexual reproduction rate of British Lemna on a year-to-year basis, or simply reflect the unusually high summer temperatures of 1995, is unclear.

The repulsive and feeding-deterrent effects of electropositive metals on juvenile sandbar sharks (Carcharhinus plumbeus)

Reducing shark bycatch and depredation (i.e., damage caused by sharks to gear, bait, and desired fish species) in pelagic longline fisheries targeting tunas and swordfish is a priority. Electropositive metals (i.e., a mixture of the lanthanide elements lanthanum, cerium, neodymium, and praseodymium) have been shown to deter spiny dogfish (Squalus acanthias, primarily a coastal species) from attacking bait, presumably because of interactions with the electroreceptive system of this shark. We undertook to determine the possible effectiveness of electropositive metals for reducing the interactions of pelagic sharks with longline gear, using sandbar sharks (Carcharhinus plumbeus, family Carcharhinidae) as a model species. The presence of electropositive metal deterred feeding in groups of juvenile sandbar sharks and altered the swimming patterns of individuals in the absence of food motivation (these individuals generally avoided approaching electropositive metal closer than ~100 cm). The former effect was relatively short-lived however; primarily (we assume) because competition with other individuals increased feeding motivation. In field trials with bottom longline gear, electropositive metal placed within ~10 cm of the hooks reduced the catch of sandbar sharks by approximately two thirds, compared to the catch on hooks in the proximity of plastic pieces of similar dimensions. Electropositive metals therefore appear to have the potential to reduce shark interactions in pelagic longline fisheries, although the optimal mass, shape, composition, and distance to baited hooks remain to be determined.

Evaluating methods for estimating rare events with zero-heavy data: a simulation model estimating sea turtle bycatch in the pelagic longline fishery

Estimating rare events from zero-heavy data (data with many zero values) is a common challenge in fisheries science and ecology. For example, loggerhead sea turtles (Caretta caretta) and leatherback sea turtles (Dermochelys coriacea) account for less than 1% of total catch in the U.S. Atlantic pelagic longline fishery. Nevertheless, the Southeast Fisheries Science Center (SEFSC) of the National Marine Fisheries Service (NMFS) is charged with assessing the effect of this fishery on these federally protected species. Annual estimates of loggerhead and leatherback bycatch in a fishery can affect fishery management and species conservation decisions. However, current estimates have wide confidence intervals, and their accuracy is unknown. We evaluate 3 estimation methods, each at 2 spatiotemporal scales, in simulations of 5 spatial scenarios representing incidental capture of sea turtles by the U.S. Atlantic pelagic longline fishery. The delta-log normal method of estimating bycatch for calendar quarter and fishing area strata was the least biased estimation method in the spatial scenarios believed to be most realistic. This result supports the current estimation procedure used by the SEFSC.

Concentrations of Polychlorinated Biphenyls (PCB’s), Chlorinated Pesticides, and Heavy Metals and Other Elements in Tissues of Belugas, Delphinapterus leucas, from Cook Inlet

Tissues from Cook Inlet beluga whales, Delphinapterus leucas, that were collected as part of the Alaska Marine Mammal Tissue Archival Project were analyzed for polychlorinated biphenyls (PCB’s), chlorinated pesticides, and heavy metals and other elements. Concentrations of total PCB’s (ΣPCB’s), total DDT (ΣDDT), chlordane compounds, hexachlorobenzene (HCB), dieldrin, mirex, toxaphene, and hexachlorocyclohexane (HCH) measured in Cook Inlet beluga blubber were compared with those reported for belugas from two Arctic Alaska locations (Point Hope and Point Lay), Greenland, Arctic Canada, and the highly contaminated stock from the St. Lawrence estuary in eastern Canada. The Arctic and Cook Inlet belugas had much lower concentrations (ΣPCB’s and ΣDDT were an order of magnitude lower) than those found in animals from the St. Lawrence estuary. The Cook Inlet belugas had the lowest concentrations of all (ΣPCB’s aver-aged 1.49 ± 0.70 and 0.79 ± 0.56 mg/kg wet mass, and ΣDDT averaged 1.35 ± 0.73 and 0.59 ± 0.45 mg/kg in males and females, respectively). Concentrations in the blubber of the Cook Inlet males were significantly lower than those found in the males of the Arctic Alaska belugas (ΣPCB’s and ΣDDT were about half). The lower levels in the Cook Inlet animals might be due to differences in contaminant sources, food web differences, or different age distributions among the animals sampled. Cook Inlet males had higher mean and median concentrations than did females, a result attributable to the transfer of these compounds from mother to calf during pregnancy and during lactation. Liver concentrations of cadmium and mercury were lower in the Cook Inlet belugas (most cadmium values were <1 mg/kg and mercury values were 0.704–11.42 mg/kg wet mass), but copper levels were significantly higher in the Cook Inlet animals (3.97–123.8 mg/kg wet mass) than in Arctic Alaska animals and similar to those reported for belugas from Hudson Bay. Although total mercury levels were the lowest in the Cook Inlet population, methylmercury concentrations were similar among all three groups of the Alaska animals examined (0.34–2.11 mg/kg wet mass). As has been reported for the Point Hope and Point Lay belugas, hepatic concentrations of silver were re

Accumulation of Heavy Metals in Franciscanas from Buenos Aires Province, Argentina

Marine mammals accumulate heavy metals in their tissues at different concentrations according to trophic levels and environmental conditions. The franciscana (Pontoporia blainvillei) is a small coastal species inhabiting the marine and estuarine areas of the Southwestern Atlantic Ocean. Its diet includes numerous species of small fish, squid and crustaceans. The aims of this study were to (i) assess the heavy metal concentration and burden distribution in different franciscana age classes and sex, and to (ii) evaluate both the accumulation processes and the transplacental transference of zinc, cadmium, copper and total mercury. Heavy metal concentrations (wet weight) were determined in eighteen dolphins by Atomic Absorption Spectrophotometry (AAS), by the cold vapour technique (mercury) or with air/acetylene flame (cadmium, zinc and copper). Liver showed the highest concentrations of mercury (max. 8.8 mg/g), zinc (max. 29.7 mg/g) and copper (max. 19.0 mg/g), whereas the highest cadmium concentrations (max. 6.7 mg/g) were found in kidney. Adults contained the highest concentrations for all heavy metals, followed by juveniles and calves in decreasing order, suggesting an age-related accumulation. No differences (p<0.05) were found between sexes within each age class. Organ burden distribution followed the same pattern for all metals and age classes: liver tissues contained maximum burdens. Mercury concentrations were higher than those of cadmium in both foetuses and newborns; and neither metal could be detected in the foetus. The analysed data suggested differences in the placental transference between metals, being significant for mercury and almost null in the case of cadmium. We can conclude that franciscana accumulates heavy metals and, due to its coastal distribution, it may be considered as a biomonitor of its environment. SPANISH: Los mamíferos marinos acumulan metales pesados en sus tejidos cuyas concentraciones están en relación con su nivel trófico y las condiciones ambientales. La franciscana (Pontoporia blainvillei) es una especie costera que habita áreas marinas y estuariales en el Atlántico Sudoccidental. Su dieta está constituída por peces, como item alimentario principal, calamares y crustáceos. El objetivo del presente trabajo es estudiar la distribución de metales pesados en diferentes clases de edad y en ambos sexos, evaluando procesos de acumulación y cargas de cadmio, mercurio total, cinc y cobre. Las concentraciones de metales pesados (en peso húmedo) fueron determinadas en dieciocho delfines por Espectrofotometría de Absorción Atómica (EAA), usando la técnica de vapor frío (mercurio) o llama de aire/acetileno (cadmio, cinc y cobre). El hígado presentó las concentraciones más altas de mercurio (máx. 8,8 mg/g), cinc (máx. 29,7 mg/g) y cobre (máx. 19,0 mg/g), mientras que las más altas de cadmio (máx. 6,7 mg/g) fueron encontradas en el riñón. Los adultos presentaron los niveles más altos, presentando los juveniles y cachorros concentraciones menores, lo cual sugirió una acumulación con la edad. No se encontraron diferencias significativas (p < 0,05) entre sexos dentro de cada clase de edad. Las cargas de metales pesados en los órganos presentaron la misma disribución para todos los metales y clases de edad. Los valores más altos fueron encontrados en el hígado, incluyendo los correspondientes a cadmio. Las concentraciones de mercurio y cadmio fueron no detectables en el feto, mientras que las de mercurio fueron superiores a las de cadmio en los cachorros. Los datos encontrados en el feto sugieren una transferencia nula a través de la placenta. Podemos concluir que P.blainvillei acumula metales pesados en sus tejidos y debido a su distribución costera, esta especie puede ser considerada como un biomonitor de su ambiente.

The history of contamination in sediments from the Mersey Estuary. Development of a chronology for the contamination of the Mersey Estuary by heavy metals and organochlorines

This is the history of contamination in sediments from the Mersey Estuary: Development of a chronology for the contamination of the Mersey Estuary by heavy metals and organochlorines Report produced by the Environment Agency in 1998. This report looks at the history of industrial contamination of the Mersey and Ribble Estuaries back to the early part of the last century, many decades before the start of monitoring programmes providing a remarkably detailed picture of very complex changes. There is a clear record in the sediment of the contamination by each heavy metal (including: Cu, Cr, Hg, Pb, Zn) and organochlorine chemical (including DDT isomers and PCB congeners) studied. The results of the study clearly show the increases in levels of contamination as industry expanded early last century followed by various improvements as this century progressed. Each pollutant has its own idiosyncratic pattern of change with some improvements predating modern environmental concerns whilst other changes seem to relate directly to recent improvements in legislative control. Overall, for the pollutants studied, the results clearly demonstrate the magnitude of improvement that has been achieved in what was a very polluted area. The only major reservation to this story is that despite the wide range of substances covered, many other potentially important pollutants remain to be studied in a similar manner.

Trace metals in common marine foods of the Pacific Coast

Trace metal analysis of 23 species of common Pacific Coast marine foods revealed high cadmium values for Bent-nosed clams (Macoma nasuta), Bay mussels (Mytilus edulis), Bay oysters (Osrtrea lurida), Pacific oysters (Crassostrea gigas), and Littleneck clams (Protothaca staminea). Metals were found to concentrate in the gills, heart, and visceral mass of all 10 species of bivalve mollusks examined. Swordfish (Xiphias gladius) and Salmon (Oncorhynchus tshawytscha) demonstrated the highest cadmium values for fish flesh.

Compliance Program report of findings: FY 79 pesticides and metals in Fish Program (7305.007)

Because fish bioaccumulate* certain chemicals, levels of chemical contaminants in their edible portion must be closely monitored. In recent years, FDA has conducted several surveys designed to determine the occurrence and levels of selected chemicals or groups of chemicals in fish. Previous fish surveillance programs included the Mercury in Wholesale Fish Survey (FY 71), the FY 73 and 74 Comprehensive Fish Surveys, the Canned Tuna Program (FY 75), the Kepone and Mirex Contamination Program (FY 77), and the FY 77 Mercury in Swordfish Program. In addition, recent Compliance Programs for Pesticides and Metals in Foods and Pesticides, Metals, and Industrial Chemicals in Animal Feed have specified coverage of fish and fish products. Because of previous findings and the sustained high level of fish imported into the United States, a separate compliance program dealing solely with chemical contaminants in fish was initiated by the FDA Bureau of Foods in FY 78. The program includes all domestic and imported fish coverage except that directed by the Bureau of Veterinary Medicine for animal feed components derived from fishery products. The earlier surveys indicated that "bottom feeder" species such as catfish generally had the highest levels of pesticides and polychlorinated biphenyls (PCBs). For this reason, coverage at these species has been emphasized. Similarly, tuna has received special attention because it is the most prevalent fish in the U.S. diet and because of potential problems with mercury. Halibut, swordfish, and snapper also were emphasized in the sampling because of potential problems with mercury levels determined in previous years. The findings in this program were used in detecting emerging problems in fish and directing FDA efforts to deal with them. Care must be exercised in drawing conclusions about trends from the data because this Compliance Program was not statistically designed. Sampling objectives and sources may vary from year to year; thus the results are not directly comparable.

Toxicity of heavy metals to brine shrimp Artemia

Bioassay were carried out on 48h cultured nauplii of brine shrimp Artemia by exposing them to seven trace elements viz. copper (Cu), zinc (Zn), cadmium (Cd), nickel (Ni), lead (Pb), iron (Fe) and manganese (Mn). Synergistic effects of all these elements and additive effects of Cu and Zn, Cd and Pb, and Ni and Fe were also investigated. Comparatively, the degree of toxicity for compound bioassays was higher than individual simple tests. The values were averaged and the expected median lethal concentration [LC sub(50)] of tested heavy metals was obtained by probit analysis on the basis of cumulative numbers of dead organisms after 24 and 48h. The order of toxicity of the metals to Artemia was Pb>Cd>Cu>Ni>Zn>Fe>Mn. Potency ratios of the seven metals were also calculated. The 24 and 48h variations obtained in LC sub(50) values were significantly different and relative implications of these are discussed.

Concentration of toxic metals in benthic organisms off Bombay coast

Concentration of toxic metals namely Zn, Cu, Fe, Cd and Pb in the marine benthos off Bombay Coast, Maharashtra (India) was estimated. Maximum concentration of Zn, Fe and Pb was from the organisms of Thana Creek. Higher concentration of Cu was encountered in benthic organisms off Versova. Cd was detected in some organisms and was maximum in the organisms collected from Mahim.

Heavy metals pollution in the coastal environment of Karachi

The marine environment near Karachi, particularly the Baba channel, Chari Kundi channel and Manora channel have been found contaminated with industrial effluents discharged by Malir and Lyari rivers, since they carry a high concentration of toxic heavy metals viz. Pb, Zn, Cu and Mn emanating from the industrial area and are received and discharged by the Lyari river. Out of 60 seawater samples collected from the above mentioned areas, Pb was present in 55 samples and Zn in 58 samples. The concentration of Pb was between 0.04 and 59.2ppm and the concentration of Zn was between 0.05 and 1.9ppm. Similarly all the 60 sludge samples collected from Lyari outfall and its adjoining area have been found to contain Pb and Zn in alarmingly high concentratios, which for Pb was between 15.4 and 3209.9ppm while for Zn was between 87 and 111.3ppm. Cu and Mn were also found in all the above samples.