Distributions of polyhalogenated compounds in Hudson River (New York, USA) fish in relation to human uses along the river

PCBs (as Aroclor concentrations) have been extensively examined in fish along the Hudson River, but other xenobiotic chemicals in fish have had limited assessment. This study determined concentrations and congener distributions of polybrominated diphenyl ethers (PBDEs), polybrominated and polychlorinated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs and PCDD/Fs), and polychlorinated biphenyls (PCBs) in smallmouth bass and striped bass taken from a 385 km reach of the Hudson River. Concentrations of PBDEs and PCBs in smallmouth bass, and PCBs in striped bass, were positively related to human uses of the compounds in the basin. Generally low levels of PCDD/Fs were found. One striped bass, however, contained elevated 2,3,7,8-TCDD, indicating exposure to a known source in the adjacent Newark Bay-Passaic River basin. PBDDs were generally below detection. PBDFs were present in four of 18 smallmouth bass, but were not detected in striped bass. Dioxin-like PCBs contribute most to 2,3,7,8-TCDD toxic equivalents in 29 of 30 samples.     

Residues of chlorpyrifos‐methyl in balsam fir foliage,forest litter,soil, stream water,sediment and fish tissue after double aerial applications of Reldan®

Abstract

Chlorpyrifos‐methyl was applied twice at 70 g A.I./ha by means of a fixed‐wing aircraft to a mixed coniferous forest near Allardville, New Brunswick. Residue in balsam fir foliage was highest (1 ppm wet wt) 1 hr after spraying and rapidly declined to about 30% within 1 day, but persisted at a very low level (0.03 ppm wet wt) for 125 days. Current year's foliage contained a higher level of residue than old foliage. Chlorpyrifos‐methyl persisted longer in forest litter than in soil. After 125 days, trace amounts (< 6 ppb wet wt) were still found in litter but were not detected in soil. In stream water the residue dissipated very rapidly; more than 90% disappeared 3 hours after the second application and were not detected after 4 days. Low‐level residue (< 0.1 ppm wet wt) was present in the sediment and persisted for 10 days. Although brook trout and slimy sculpin captured in the stream within 3 days of the second application contained residues (< 0.05 ppm fresh wt) none were detected in any fish captured, 9 and 47 days later.     

Nationwide monitoring of mercury in wild and farmed fish from fresh and coastal waters of Korea

Mercury (Hg) concentrations were monitored in wild and cultured fish collected from fresh and coastal waters in the Korean peninsula from April 2006 to August 2008 nationwide. Total Hg concentrations were reported for 5043 fish samples, including 78 species from 133 locations. Significant interspecies variation was noted in the Hg levels. The average Hg concentration in each fish species ranged from 6.31 μg kg⁻¹ for mullet (Mugil cephalus) to 200 μg kg⁻¹ for mandarin fish (Siniperca scherzeri). Among the species collected, the maximum concentration of Hg, 1720 μg kg⁻¹, was measured in an Amur catfish (Silurus asotus). Only wild freshwater fish exceeded the WHO ingestion standard. Wild freshwater piscivorous fish samples from a large artificial upstream lake contained the highest Hg levels. Hg concentrations were compared between fish groups categorized as wild and farmed fish from freshwater and coastal waters. Although the wild freshwater fish had similar size ranges, their Hg concentrations were higher than those of the other groups. Compared to the feed of farmed marine and freshwater fishes, the prey of wild freshwater fish had a higher Hg concentration, and the total Hg concentrations in freshwater and associated sediment samples were higher than those in coastal water and associated sediment samples. In the freshwater environment, piscivorous fish bioaccumulated two times more Hg than carnivorous and omnivorous fish and four times more than planktivorous fish. The difference in Hg concentrations among trophic groups might have been due to differences in the size of fish, in addition to the variations among different trophic groups. These data will be useful for developing the fish consumption advisory as a management measure to reduce Hg exposure.     

MODELKEY. Models for assessing and forecasting the impact of environmental key pollutants on freshwater and marine ecosystems and biodiversity (5 pp)

BACKGROUND: Triggered by the requirement of Water Framework Directive for a good ecological status for European river systems till 2015 and by still existing lacks in tools for cause identification of insufficient ecological status MODELKEY (http:// www.modelkey.org), an Integrated Project with 26 partners from 14 European countries, was started in 2005. MODELKEY is the acronym for 'Models for assessing and forecasting the impact of environmental key pollutants on freshwater and marine ecosystems and biodiversity'. The project is funded by the European Commission within the Sixth Framework Programme. OBJECTIVES: MODELKEY comprises a multidisciplinary approach aiming at developing interlinked tools for an enhanced understanding of cause-effect-relationships between insufficient ecological status and environmental pollution as causative factor and for the assessment and forecasting of the risks of key pollutants on fresh water and marine ecosystems at a river basin and adjacent marine environment scale. New modelling tools for risk assessment including generic exposure assessment models, mechanistic models of toxic effects in simplified food chains, integrated diagnostic effect models based on community patterns, predictive component effect models applying artificial neural networks and GIS-based analysis of integrated risk indexes will be developed and linked to a user-friendly decision support system for the prioritisation of risks, contamination sources and contaminated sites. APPROACH: Modelling will be closely interlinked with extensive laboratory and field investigations. Early warning strategies on the basis of sub-lethal effects in vitro and in vivo are provided and combined with fractionation and analytical tools for effect-directed analysis of key toxicants. Integrated assessment of exposure and effects on biofilms, invertebrate and fish communities linking chemical analysis in water, sediment and biota with in vitro, in vivo and community level effect analysis is designed to provide data and conceptual understanding for risk arising from key toxicants in aquatic ecosystems and will be used for verification of various modelling approaches. CONCLUSION AND PERSPECTIVE: The developed tools will be verified in case studies representing European key areas including Mediterranean, Western and Central European river basins. An end-user-directed decision support system will be provided for cost-effective tool selection and appropriate risk and site prioritisation.     

Design-based estimators and power analyses of trend tests for the proportion of fish that exhibit gross pathological disorders

Methods for estimating the proportion of fish that exhibit gross pathological disorders and for estimating the variance of these estimates are defined. The methods are for the situation in which a probability-based sampling design is used to collect fish for examination, but geographic locations (rather than individual fish) are assigned probabilities of being selected for sampling. To illustrate the use of the methods, they are applied to data collected during the 1992 EMAP- Estuaries sampling program in the Louisianian Province (i.e., the Gulf of Mexico). Separate estimates of the proportion of fish with gross pathological disorders are computed for demersal species, commercial species, pelagic species, and all species as one group. In addition, a test for trend in the proportion of fish that exhibit gross pathological disorders is defined, and analyses of the power of the test are presented. The power analyses are based on a general underlying model of the random distribution patterns of fish and the random process of catching fish. The power analyses also take into account the features of the sampling designs used for collecting fish. Component parameter estimates were computed using data from the 1992 EMAP-Estuaries sampling program in the Louisianian Province. Results from these analyses suggest that the EMAP-Estuaries sampling designs are capable of detecting a 0.15% change per year in the proportion of fish (all species groups combined) with gross pathological disorders in estuaries of the Louisianian Province over a 12-year period with a power of at least 80%. © Rapid Science 1998     

Comparison of Outcomes of Permanently Closed and Periodically Harvested Coral Reef Reserves

Abstract: In many areas of the developing world, the establishment of permanent marine reserves is inhibited by cultural norms or socioeconomic pressures. Community conserved areas that are periodically harvested are increasingly being implemented as fisheries management tools, but few researchers have empirically compared them with permanently closed reserves. We used a hierarchal control‐impact experimental design to compare the abundance and biomass of reef fishes, invertebrates, and substrate composition in periodically harvested and permanent reserves and in openly fished (control sites) of the South Pacific island country of Vanuatu. Fished species had significantly higher biomass in periodically harvested reserves than in adjacent openly fished areas. We did not detect differences in substratum composition between permanent reserves and openly fished areas or between permanent reserves and periodically harvested reserves. Giant clams (tridacnids) and top shells (Trochus niloticus) were vulnerable to periodic harvest, and we suggest that for adequate management of these species, periodically harvested community conservation areas be used in conjunction with other management strategies. Periodic harvest within reserves is an example of adaptive and flexible management that may meet conservation goals and that is suited to the social, economic, and cultural contexts of many coastal communities in the developing world.