Background Mercury Concentrations in River Water in Maine, U.S.A.

Mercury concentrations in 58 rivers in Maine was measured to range from below detection up to 7.01 ng L^-1 and averaged 1.80±1.29 ng L^-1. The concentration gradient for mercury in rivers across the state was not uniform. Mercury strongly correlated with dissolved organic carbon (DOC) and aluminum, and less strongly with copper, lead, and zinc. Mercuryexhibited significant differences in correlations with chemical variables and local geology when partitioned by flow state (high or low). Mercury concentrations were greatest in rivers flowingacross either wacke-type bedrock at low metamorphic grade, or glacial-till deposits. Elevated concentrations of mercury formed a locus in northern Maine under both high and low-flow states while in southwestern Maine a locus formed only during high-flowstates. These regional differences were statistically significantwhen compared by geographical location. We suggest that there is a bedrock source of mercury in northeastern Maine that is dilutedduring periods of high runoff. The elevated concentrations detected under high-flow states, as noted in southwestern Maine, may reflect mercury released from storage in association withDOC during periods of high runoff. The association of mercury with flow state indicates that watershed processes and local geology can modulate the concentration of mercury in rivers.     

Impact of Coal Power Plant Emission on the Foliar Elemental Concentrations in Plants in a Low Rainfall Tropical Region

A field study was conducted around two thermal power plants of India to quantify the changes in foliar elemental concentrations due to emission in a low rainfall tropical area. Sulphur dioxide and particulates were at high levels which may cause serious ecological effects. Emission from the power plants has altered the elemental concentrations in the leaves of evergreen and deciduous plants. The foliar total-S and SO₄ ^2–-S levels were significantly higher in all the plants growing at polluted sites. However, the organic-S content was more or less unaltered. In evergreen plants, the SO₄ ^2–-S content increased gradually from summer through winter, whereas in the deciduous plants there was a higher magnitude of increase after onset of new leaves during summer. With the increasing pollution load, foliar Ca²⁺ and K⁺ contents increased, whereas N content decreased. The reduction in N content was greater during summer in evergreen plants and during winter in deciduous plants. The plants growing closer to the power plants accumulated more trace elements (Mn, Fe, Cd, Pb and Ni) as compared to those growing at distant sites. In deciduous plants the leaf fall during winter lowered down the trace element     

The Radial Increment and Stemwood Element Concentrations of Scots Pine in the Area Influenced by the Narva Power Plants in Northeast Estonia

Soil is an important component of a watershed. Understanding soils and their interactions with the other components are, thus, considered to be critical and essential for conservation of resources and management of the watershed. Development of soil sampling and analysis programs are crucial for these purposes. Site-specific soil data are needed to identify current soil characteristics, as well as to validate datasets gathered for watershed-scale modelling of non-point sources (NPS) of pollutants arising from various land-use activities, hydrodynamics and water quality. The Koycegiz Lake–Dalyan Lagoon watershed, located in the southwest of Turkey along the Mediterranean Sea Coast, was selected as the study area for watershed modelling purposes. Development of soil sampling plans, their practical optimization, soil analyses and interpretation are presented in this article. The soil analyses conducted include physical, chemical and specific soil characteristics. Within the framework of this study, soil fertility parameters are presented and evaluated. Such an approach used is recommended for especially developing countries where up-to-date data sets are not fully available and/or centrally publicized.     

Temporal and Spatial Variations in Nitrogen Dioxide Concentrations Across an Urban Landscape: Cambridge, UK

The acquisition of a comprehensive air quality dataset for a small city environment is described for use in statistical modelling of dispersion processes and micro-scale assessment of polluted zones. The dataset is based on a nitrogen dioxide diffusion tube survey for Cambridge where up to 80 roadside and background sites have been monitored continuously over two years, using a two week exposure period. Site categories are defined by their function within the urban landscape. Spatial and temporal features of the data set are explained in terms of urban location, street geometry, meteorology and traffic behaviour. The highest levels of NO2 are found in central canyon streets which are narrow with enclosing architecture and slow-moving traffic. In contrast lower levels are found for the wider, more open radial routes where traffic is free-flowing. The influence of street geometry on NO2 levels for central streets is demonstrated, where canyon sections adjacent to open sections having the same traffic flow record higher concentrations. Whilst all roadside sites are affected by a photochemical pollution 'episode', the greater potential for elevated NO2 concentrations within the canyon sections is significant. The close proximity of low background levels of NO2 to roadside 'hot-spots' is important for public exposure assessment. The variation in background levels across the urban landscape is very small and unrelated to location; whether central, suburban or outer city. Seasonal variation, not seen in roadside data, is clearly apparent in background data with a winter maximum and summer minimum.     

Biomonitoring in the Boulder River Watershed, Montana, USA: Metal Concentrations in Biofilm and Macroinvertebrates, and Relations with Macroinvertebrate Assemblage

Portions of the Boulder River watershed contain elevated concentrations of arsenic, cadmium, copper, lead, and zinc in water, sediment, and biota. We measured concentrations of As, Cd, Cu, Pb, and Zn in biofilm and macroinvertebrates, and assessed macroinvertebrate assemblage and aquatic habitat with the objective of monitoring planned remediation efforts. Concentrations of metals were generally higher in downstream sites compared with upstream or reference sites, and two sites contained metal concentrations in macroinvertebrates greater than values reported to reduce health and survival of resident trout. Macroinvertebrate assemblage was correlated with metal concentrations in biofilm and macroinvertebrates. However, macroinvertebrate metrics were significantly correlated with a greater number of biofilm metals (8) than metals in invertebrates (4). Lead concentrations in biofilm appeared to have the most significant impact on macroinvertebrate assemblage. Metal concentrations in macroinvertebrates were directly proportional to concentrations in biofilm, indicating biofilm as a potential surrogate for monitoring metal impacts in aquatic systems.     

Aldehyde Concentrations in Ambient Air of Coastal Georgia, U.S.A.

Aldehydes are an airborne byproduct of many industrialprocesses, vehicle transportation, and emissions fromnumerous natural sources. To characterize aldehydeconcentrations in ambient air of the Savannah, Georgiaarea, air samples for 3 aldehydes (formaldehyde,acetaldehyde, and propionaldehyde) were collected atfive sites on a monthly basis over a 12-month periodfrom December of 1995 through November 1996. Four ofthe sites were in central Savannah and the fifth sitewas located in a rural area about 56 km south ofSavannah. During each 24-hr sampling episode, sampleswere collected in two 12-hr periods approximatingdaylight and nighttime hours, following U.S. EPAMethod TO-11. Formaldehyde concentrations ranged from0.17 to 6.80 g m^-3, acetaldehydeconcentrations ranged from 0.07 to7.60 g m^-3, and propionaldehyde levels rangedfrom 0.02 to 9.10 g m^-3. On average, thefour sites in Savannah had higher aldehydeconcentrations than the rural site (2.0 versus1.2 g m^-3 for formaldehyde, 2.3 versus1.7 g m^-3 for acetaldehyde, and 1.2 versus1.0 g m^-3 for propionaldehyde). The daytimeconcentrations for formaldehyde and acetaldehyde werehigher than the nighttime levels. The data from allthe sites were within published worldwide backgroundvalues for aldehydes.     

Ammonia Monitoring in Switzerland with Passive Samplers: Patterns, Determinants and Comparison with Modelled Concentrations

Gaseous ammonia (NH3) is an important form of N deposition to ecosystems, but it is not being routinely monitored in Switzerland. Therefore, a study was conducted to estimate annual means and seasonal patterns of NH3 concentrations for different site types in Switzerland, and to compare annual measured and modelled NH3 concentrations. NH3 concentrations were measured using the 'Zürcher' passive sampler, a Palmes type sampler with an acidic solution as absorbent. Twenty-four sampling sites were run for one year, and 17 for two years. The samplers were changed fortnightly or monthly. Spatial emission patterns were mapped by combining information on (1) the location of emission sources, (2) national statistics on NH3-emitting activities and (3) activity-specific emission factors. The spatial resolution was one hectare. The mean annual NH3 concentration in the ambient air of the 41 sites was 2.5+/-0.3 microg m(-3) (mean+/-standard error). It ranged from 0.4 to 7.5 microg m(-3). The site type and the season were the most important factors explaining the variation in the seasonal mean concentration. NH3 concentrations were highest in intensively used agricultural areas and in cities, and lowest in Alpine sites remote from emission sources. At 39 out of 41 sites, the NH3 concentrations were higher in summer (3.1+/-0.3 microg m(-3)) than in winter (2.0+/-0.3 microg m(-3)). Modelled NH3 concentrations did not systematically deviate from measured concentrations (r2 = 0.69). With the combined monitoring and modelling approach, it is now possible to obtain a reasonable and consolidated picture of the overall NH3 situation in Switzerland.     

A Simple Model of Pollutant Concentrations in a Street Canyon

A single compartment model has been constructed for predicting hourly concentrations of pollutant concentrations arising from vehicular emissions within a typical street canyon. The model takes account of traffic densities and composition to estimate pollutant emissions within the model compartment. Meteorological data on wind speed and direction are used to define the exchanges of pollutants between the compartment and the surrounding air. A parameter is also included to describe the exchange in calm conditions. The pollutant concentrations are then estimated from a steady state mass balance equation for the compartment, assuming conservation of pollutants. The model was applied to the prediction of carbon monoxide concentrations in Hope Street, Glasgow. Model parameters were fitted using field measurements, together with concurrent meteorological data and traffic flows estimated from traffic census data for Hope Street. The model accounted well for the observed variations in carbon monoxide. It was found that the model parameters varied seasonally, perhaps due to differences in atmospheric stability which have not so far been included in the model formulation.     

Mercury Contamination of Biota from Acadia National Park, Maine: A Review

We reviewed literature reporting both total and methylmercury from biota from Acadia National Park, Maine, USA. Our review of existing data indicates that 1) mercury contamination is widespread throughout the Park’s various aquatic ecosystems; 2) mercury pollution likely represents a moderate to high risk to biota inhabiting the Park; and 3) biota at all trophic levels possess elevated concentrations of both total and methylmercury. Watershed fire history and the resulting post-fire forest succession patterns are an important landscape attribute governing mercury cycling at Acadia National Park. Therefore, park service personnel should consider these factors when planning and implementing Hg biomonitoring efforts. Additional baseline funding from the National Park Service for Hg research and biomonitoring will likely be required in order to further evaluate the spatial and temporal patterns of mercury contamination in the park’s biota. An erratum to this article can be found at     

Concentrations and profiles of polychlorinated biphenyls, -dibenzo-p-dioxins and -dibenzofurans in livers of mink from South Carolina and Louisiana,U.S.A

In South Carolina, U.S.A., mink have been reintroduced from two apparently healthy populations to areas where populations haveexisted in the past but have been extirpated. High mortality wasobserved during transport of mink from the source populations. Inorder to elucidate the potential effects of dioxin-like compoundson the survival and reproduction of mink, concentrations of totalpolychlorinated biphenyls (PCBs), p,p-DDE, dioxin-likePCBs, polychlorinated dibenzo-p-dioxins (PCDDs), anddibenzofurans (PCDFs) were measured in livers of mink collectedfrom the source populations in South Carolina and Louisiana. Concentrations of total 2,3,7,8-tetrachlorodibenzo-p-dioxinequivalents (TEQs) for the South Carolina and Louisiana mink were21 and 14 pg g^-1, wet wt., respectively. PCB and TEQ concentrations were close to the threshold values that can, under laboratory conditions, elicit toxic effects in ranchmink. Therefore, any additional exposures of these populations toTEQs might adversely affect their populations.     

Heavy Metal Concentrations in Water, Sediment, Fish and Some Benthic Organisms from Tigris River, Turkey

In this study concentrations of heavy metals, such as Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn were determined in water, sediment, muscle, liver and gill of fish (Silurus triostegus, Mastacembelus simack, Mystus halepensis, Orthrias euphraticus) the muscle and liver of crab (Potamon fluviatilis), the internal organs of fresh water snail (Physa acuta), and mussel (Unio elongatulus), and in whole biomass of green algae (Spirogyra sp.) examples collected seasonally from three selected sites (I, II, and III) of Tigris River and from a reference site on Resan Creek. In general, the average Cd, Cu, Mn, Ni, Zn, and Fe values in Sites I, II, and III were found to be high in spring and summer. The concentrations of heavy metals in the Tigris River are compared with previous studies in the same sites. The results showed that Cu levels have gradually decreased during recent years. In Tigris River, among the living organisms, i.e., those which are living in benthic region and showing biomonitor characteristic, crab, snail, green algae, mussel and fish are seen to be formed in sequence. Cu, Fe, Mn and Zn values obtained from the muscle of fish and from the mass of internal organs of mussel and snail were found to be under the acceptable values suggested.     

Relationships Between Toxicity and Concentrations of Chemical Contaminants in Sediments from Sydney Harbour, Australia, and Vicinity

Correlation analyses between measures of toxicity and concentrations of chemical contaminants were conducted for 103 surficial sediments from Sydney Harbour, Australia, and vicinity. Toxicity tests consisted of amphipod survival and reburial tests of whole sediments (Corophium colo), sea urchin fertilisation and larval development tests of pore waters (Heliocidaris tuberculata) and microbial bioluminescence (Microtox) tests of solvent extracts and pore waters. Toxicity in most tests correlated with concentrations of metallic contaminants, in particular, zinc, lead and copper. Organic contaminants did not correlate as significantly with toxicity. However, Heliocidaris tuberculata showed relationships with organochlorine compounds in samples with low to moderate metals contamination. Toxicity in the Microtox solvent extract test appeared to be primarily influenced by the presence of sulfur. This study has no precedent in Australia and the results support the validity of using local indigenous species in toxicity tests of field-collected sediments. This toxicity/chemistry dataset may be used in evaluations of sediment quality guidelines recently introduced to Australia.     

Concentrations, sources and temporal trends in atmospheric polycyclic aromatic hydrocarbons in a major conurbation

Concentrations of atmospheric PAH were separately determined in total suspended particulate matter and associated vapour phase in ambient air in Birmingham, UK. Samples of 24 h duration were taken simultaneously at two locations (the Bristol Road Observatory Site, BROS, and the Elms Road Observatory Site, EROS) on 44 separate occasions every one to two weeks between October 1999 and January 2001. BROS was 10 m from the busy Bristol Road, 800 m from EROS that was located within the "green space" of the University of Birmingham campus. With the exception of acenaphthene, average concentrations of all measured PAH at BROS exceed those at EROS, with a paired t-test revealing these roadside increments to be significant (p < 0.05) for 9 out of the 16 target PAH, demonstrating the importance of traffic emissions of PAH. Although the declines were not statistically significant (p > 0.05) except for phenanthrene and fluoranthene, concentrations of individual PAH at EROS between July and December inclusive in 1999 and 2000 fell by between 16 and 54% compared with those during the same months in 1997. Multiple linear regression of PAH concentrations against meteorological variables confirmed the influence of the Bristol Road on BROS but not EROS. Cluster analysis of PAH contamination in individual samples showed there to be two statistically distinct groups of samples. One group contained 15 samples, all of which displayed elevated concentrations. Examination of air mass back trajectory data, revealed that these PAH pollution episodes originate due to the combined effects of meteorology and local traffic emissions, rather than as a result of long-range transport. Eighteen 12 h samples were also taken at EROS over the period of the November Bonfire Night festivals of 1999 and 2000. These revealed significantly elevated PAH concentrations on the nights when ignition of bonfires and fireworks would be anticipated to peak. These results are relevant to assessments of the impact of similar "festivals of fire" elsewhere. In particular, retene (7-isopropyl-1-methylphenanthrene) concentrations were especially elevated, indicating it has possible utility as an indicator of wood combustion emissions.     

Concentrations of As, Be, Cr, Hg, Mn, and Ni in ambient air at four urban locations in Japan

The metal concentrations of As, Be, Cr, Hg, Mn, and Ni in ambient air were measured at four sites in Japan from October 1997 to March 2006. The mean metal concentration data measured from the four sites (K1, K2, M, and Y) are found on the order of Mn > Cr–Ni > As > Hg > Be. The concentrations of Mn with the highest mean value were fairly variable across four sites such as 45.9 ± 42.8 (K1), 25.6 ± 19.4 (K2), 22.5 ± 19.7 (M), and 25.4 ± 19.8 ng m^???3 (Y). In contrast, the concentrations of Be with the lowest mean value were less variable across four sites with means of 0.03 to 0.04 ng m^???3. Inspection of the seasonal patterns indicates the peak occurrence of most metals during spring, although relative dominance during winter is seen at the most polluted area (K1). Evaluation of long-term patterns indicates that the noticeably high values of metals in the early stage of study reduced gradually across the years, although the metal concentration levels in most areas were affected significantly by anthropogenic activities. However, efforts to control pollution levels seemed to gradually contribute to a decrease in metal concentration levels of all study sites through the years.     

Spatial and Temporal Variations in Trace Metal Concentrations in the Cockle, Austrovenus Stutchburyi from Otago, New Zealand

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993–1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (μg g⁻¹ dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3–60 μg g⁻¹ for Cu, 40–118 μg g⁻¹ for Zn, 2–12 μg g⁻¹ for Mn, 5–35 μg g⁻¹ for Ni and 1–44 μg g⁻¹ for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.     

Concentrations of Cu, Fe, Mn, and Zn in tropical soils amended with sewage sludge and composted sewage sludge

Sewage sludge may be used as an agricultural fertilizer, but the practice has been criticized because sludge may contain trace elements and pathogens. The aim of this study was to compare the effectiveness of total and pseudototal extractants of Cu, Fe, Mn, and Zn, and to compare the results with the bioavailable concentrations of these elements to maize and sugarcane in a soil that was amended with sewage sludge for 13 consecutive years and in a separate soil that was amended a single time with sewage sludge and composted sewage sludge. The 13-year amendment experiment involved 3 rates of sludge (5, 10, and 20 t ha^?1). The one-time amendment experiment involved treatments reflecting 50, 100, and 200 % of values stipulated by current legislation. The metal concentrations extracted by aqua regia (AR) were more similar to those obtained by Environmental Protection Agency (EPA) 3052 than to those obtained by EPA3051, and the strongest correlation was observed between pseudo(total) concentrations extracted by AR and EPA3052 and bioavailable concentrations obtained by Mehlich III. An effect of sewage sludge amendment on the concentrations of heavy metals was only observed in samples from the 13-year experiment.     

Radionuclide Concentrations in Benthic Invertebrates from Amchitka and Kiska Islands in the Aleutian Chain, Alaska

Concentrations of 13 radionuclides (¹³⁷Cs, ¹²⁹I, ⁶⁰Co, ¹⁵²Eu, ⁹⁰Sr, ⁹⁹Tc, ²⁴¹Am, ²³⁸Pu, ^239,249Pu, ²³⁴U, ²³⁵U, ²³⁶U, ²³⁸U were examined in seven species of invertebrates from Amchitka and Kiska Islands, in the Aleutian Chain of Alaska, using gamma spectroscopy, inductively coupled plasma mass spectroscopy, and alpha spectroscopy. Amchitka Island was the site of three underground nuclear test (1965–1971), and we tested the null hypotheses that there were no differences in radionuclide concentrations between Amchitka and the reference site (Kiska) and there were no differences among species. The only radionuclides where composite samples were above the Minimum Detectable Activity (MDA) were ¹³⁷Cs, ²⁴¹Am, ^239,249Pu, ²³⁴U, ²³⁵U, ²³⁶U, and ²³⁸U. Green sea urchin (Strongylocentrotus polyacanthus), giant chiton (Cryptochiton stelleri), plate limpets (Tectura scutum) and giant Pacific octopus (Enteroctopus dofleini) were only tested for ¹³⁷Cs; octopus was the only species with detectable levels of ¹³⁷Cs (0.262 ± 0.029 Bq/kg, wet weight). Only rock jingle (Pododesmus macroschisma), blue mussel (Mytilus trossulus) and horse mussel (Modiolus modiolus) were analyzed for the actinides. There were no interspecific differences in ²⁴¹Am and ^239,240Pu, and almost no samples above the MDA for ²³⁸Pu and ²³⁶U. Horse mussels had significantly higher concentrations of ²³⁴U (0.844 ± 0.804 Bq/kg) and ²³⁸U (0.730 ± 0.646) than the other species (both isotopes are naturally occurring). There were no differences in actinide concentrations between Amchitka and Kiska. In general, radionuclides in invertebrates from Amchitka were similar to those from uncontaminated sites in the Northern Hemisphere, and below those from the contaminated Irish Sea. There is a clear research need for authors to report the concentrations of radionuclides by species, rather than simply as ‘shellfish’, for comparative purposes in determining geographical patterns, understanding possible effects, and for estimating risk to humans from consuming different biota.     

Concentrations of Arsenic, Cadmium, Copper, Lead, Selenium, and Zinc in Fish from the Mississippi River Basin, 1995

Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 12 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB), and in late 1996 from a reference site in West Virginia. The NCBP sites represented key points (dams, tributaries, etc.) in the largest rivers of the MRB. The NAWQA sites were typically on smaller rivers and were selected to represent dominant land uses in their watersheds. The West Virginia site, which is in an Eastern U.S. watershed adjacent to the MRB, was selected to document elemental concentrations in fish used for other aspects of a larger study and to provide additional contemporaneous data on background elemental concentrations. At each site four samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio, 'carp') or black bass (Micropterus spp., 'bass') of the same sex, were collected. The whole fish were composited by station, species, and gender for analysis of arsenic (As), lead (Pb), and selenium (Se) by atomic absorption spectroscopy and for cadmium (Cd), copper (Cu), and zinc (Zn) by inductively-coupled plasma emission spectroscopy. Concentrations of most of the elements examined were lower in both carp and bass from the reference site, a small impoundment located in a rural area, than from the NCBP and NAWQA sites on rivers and larger impoundments. In contrast, there were few overall differences between NCBP sites NAWQA sites. The 1995 results generally confirmed the continued weathering and re-distribution of these elemental contaminants in the MRB; concentrations declined or were unchanged from 1984-1986 to 1995 at most NCBP sites, thus continuing two-decade trends. Exceptions were Se at Station 77 (Arkansas R. at John Martin Reservoir, CO), where concentrations have been elevated historically and increased slightly (to 3.8-4.7 microg g-(1) in bass and carp); and Pb, Cd, and Zn at Station 67 (Allegheny R. at Natrona, PA), where levels of these metals were high in the past and increased from 1986 to 1995.     

Mercury, Methylmercury, and Selenium Concentrations in Eggs of Common Loons (Gavia immer) from Canada

Concentrations of Hg and Se were determined for a total of 125Common Loon (Gavia immer) eggs collected from lakes in Alberta, Saskatchewan, Ontario, Quebec, New Brunswick and NovaScotia, Canada between 1972 and 1997. Resulting data were compared to Hg and/or Se concentrations known or suspected tocause reproductive impairment in birds. Organic (methyl) Hg analyses were also performed on a subset of 24 loon eggs. Thirty-nine of 125 eggs had total Hg levels exceeding those (0.6 g g^-1 ww, or 2.5 g g^-1 dw)previously reported to be associated with reproductive impairment in common loons (Barr, 1986), and 9 of 125 eggshad Hg concentrations higher than the level associated withreproductive impairment in birds generally 1 g g^-1 ww; (Thompson, 1996). Selenium concentrations in loon egg samples were less than levels known to cause reproductiveimpairment in birds. A weak but significant positive correlation was observed between egg-Hg and -Se concentrations(r = 0.511, p < 0.05). On average, methylmercury accounted for about 87% of total Hg in 24 eggs analysed for both total and organic Hg. In this subset of eggs, the relationship between organic (methyl) Hg and Se was significant (r = 0.538, p = 0.007) while that found between inorganic Hg and Se in the same eggs was not significant (r = 0.353, p = 0.091). This relationship was unexpected and was contrary to relationships established for organic and inorganic Hg vs. Se in adult loon liver and kidney tissue (Scheuhammer et al., 1998b).     

Mercury Concentrations in Fish from Lake Meredith, Texas: Implications for the Issuance of Fish Consumption Advisories

We examined how length of fish is related to mercury concentrations in muscle tissue of seven species of fish from Lake Meredith, Texas and determined how sex and growth rate are related to mercury concentration in walleye (Sander vitreus). Flathead catfish (Pylodictis olivaris), walleye and white bass (Morone chrysops) had the highest concentrations of mercury and channel catfish (Ictalurus punctatus), common carp (Cyprinus carpio), river carpsucker (Carpiodes carpio) and gizzard shad (Dorosoma cepedianum) had the lowest concentrations of mercury. Mercury concentrations were positively correlated with total length (TL) of fish for all species except gizzard shad, which exhibited a negative correlation between mercury concentration and TL. Male walleye grew more slowly than females, and males had higher concentrations of mercury than females. We also assessed the differences in fish consumption advisories that would be issued using Texas Department of State Health Services (DSHS) guidelines versus United States Environmental Protection Agency (USEPA) recommendations. Using DSHS guidelines, no fish species in Lake Meredith would be issued a fish consumption advisory. Nevertheless, DSHS has issued an advisory for walleye in Lake Meredith, possibly due to an inadequate sample size of fish. Using USEPA guidelines, a fish consumption advisory would be issued for the largest size class of flathead catfish but no advisory exists for flathead catfish in Lake Meredith. We suggest that when fish in a lake may be contaminated with mercury, all game fish in the lake should be assessed, and mercury advisories should take fish size into account.