Biological effects of contaminants: Stress on Stress (SoS) response in mussels

The SoS biomarker provides evidence of the effects of pollutants at the whole organism response level. It shows a typical dose-response curve, characterized by a continuous decrease of the parameter LT50 (the median survival time or the time (days) in which 50% of mussels have died) with increasing pollutant concentrations. However, in some experiments with low concentrations of contaminants a slight increase in LT50 has beeno bserved, possibly due to a hormetic effect. The method for determining SoS in mussels is being applied routinely to both toxicant-exposed mussels in laboratory studies and to mussels collected in national monitoring programmes from polluted environments and along pollution gradients. The added value of SoS in mussels is that this response measures the overall impact of multiple stressors on an organism. Thus, SoS responses can be quantitatively correlated to contaminant tissue concentrations, providing an integrated biological effect–chemical monitoring tool.Postprin

In vitro ecotoxicological assessment of pelagic ecosystems

The ICES biological effects monitoring in pelagic ecosystems (BECPELAG) workshop is a multi-national, multi-disciplinary workshop aimed at establishing suitable techniques for monitoring the effects of contaminants on pelagic ecosystems. One of the many activities that have been performed concurrently is the extraction of water samples using semi-permeable membrane devices (SPMDs) and large volume solid phase extraction (SPE) followed by in vitro testing and targeted chemical analysis of the concentrated extracts. The following in vitro assays were used: DR-CALUX, yeast oestrogen and androgen screen (YES & YAS), blue mussel (Mytilus edulis) embryo, Tisbe battagliai, and Skeletonema costatum. Data from the study are presented along with recommendations on procedures for the use of in vitro in the monitoring of the pelagic environment

Supporting variables for biological effects measurements in fish and blue mussels

Biological effects measurements in fish and blue mussel are fundamental in marine environmental monitoring. Nevertheless, currently used biomarkers may be confounded by basic physiological phenomena, such as growth, reproduction, and feeding, as well as thereby associated physiological variation. Here, we present a number of supporting variables, which are essential to measure in order to obtain reliable biological effects data, facilitate their interpretation, and make valid comparisons. For fish, these variables include: body weight, body length, condition, gonad maturation status, various somatic indices, age, and growth. For blue mussels, these variables include: volume, flesh weight, shell weight, and condition. Also, grossly visible anomalies, lesions, and parasites should be recorded for both fish and blue mussels. General confounding factors and their effects are described, as well as recommendations for how to handle themPostprint

Biological effects of contaminants: Stress on Stress (SoS) response in mussels

It is well known that the physiological status of marine organisms changes when they are exposed to contaminants (Bayne et al., 1986; De Zwaan et al., 1995; Viarengo et al., 1995). One consequence is that the organism is less able to tolerate the natural fluctuations of environmental factors. Mussels can tolerate aerial exposure for many days but, under sustained aerial exposure, they will eventually die. The ability of mussels to keep valves closed and to resist aerial exposure relates to the amount of adenosine triphosphate (ATP) available to fuel the adductor muscle (De Zwaan and Mathiew, 1992). In mussels from contaminated sites, part of the metabolic energy is spent on detoxification processes, thus depleting the ATP needed for other physiological functions. The reduction of survival in air, or stress on stress (SoS) biomarker, is a simple and lowcost whole organism response that can show pollutant induced alterations in the organism’s physiology that renders the animal more sensitive to further environmental changes...

Toxicity characterization of organic contaminants in Industrialized UK estuaries and coastal waters

This report describes the isolation and identification of organic toxicants present in marine surface waters collected from industrially impacted areas around the UK in 1997. The characterization process utilized Toxicity Identification Evaluation (TIE) procedures that have been adapted for marine samples and a small volume bioassay using the marine copepod Tisbe battagliai. The dissolved organic content of bulk water samples was isolated using a layered solid phase extraction system to provide sample concentrates which were tested for acute toxicity. Where acute toxicity was demonstrated, the extracts were fractionated using reverse phase HPLC and tested further. Each fraction showing toxicity was then analysed by gas chromatography-mass spectrometry. The results of this investigation demonstrate that surface water concentrates collected from several impacted estuaries show acute toxicity. Organic extracts from surface waters may be concentrated using simple chromatographic techniques to induce toxicity in test species. Fractionation showed that the majority of this toxicity is associated with low to medium polarity contaminants. Compounds that were identified by gas chromatography-mass spectrometry as the possible cause of toxic effect include alkylphenols, alkyl substituted naphthalenes, alkyl-substituted fluorenes and dimethyl benzoquinone, however, the identity of certain toxic compounds remains unknown. It is concluded that the technique is a valuable tool in identifying compounds that may be potentially harmful to the aquatic environment. Copyright (C) 1999

Identification of in vitro estrogen and androgen receptor agonists in North Sea offshore produced water discharges

The estrogen receptor (ER) agonist potency of offshore produced water discharges was examined via bioassay-directed chemical analysis. The in vitro estrogen receptor (ER) and androgen receptor (AR) agonist potency of five produced water samples collected from oil-production platforms in the British and Norwegian sectors of the North Sea was determined by using the yeast estrogen and androgen screens. Produced water samples were extracted in situ on the production platforms by using large-volume solid-phase extraction. All five extracts tested positive for the presence of ER agonists, whereas no AR agonist activity could be detected. By using the yeast estrogen screen assay in association with bioassay-directed fractionation, attempts were made to identify the ER agonist compounds present in the produced water extracts. The fractionation procedure used cyano-amino-bonded silica normal-phase high-performance liquid chromatography to isolate estrogenic compounds from produced water extract followed by full-scan gas chromatography-electron-impact mass spectrometry (GC-(EI)MS) to identify them. Isomeric mixtures of C to C and C alkylphenols contributed to the majority of the ER agonist potency measured in the samples

Bio-analytical and chemical characterisation of offshore produced water effluents for estrogen receptor (ER) agonists

The in vitro estrogen receptor (ER) agonist potency and C to C alkyl substituted phenol content of offshore produced water effluents collected from the UK sector of the North Sea were determined using a combination of bio-analytical and chemical analysis techniques. An in vitro reporter gene assay was used to determine ER agonist potency, whilst gas chromatography coupled to mass spectrometry (GC-MS) was used to quantify the concentration of alkylphenols. The in vitro ER agonist potency was highly variable and ranged from less than the limit of detection (theoretically 0.03 ng 17β-estradiol (E2) l) to 91 ng E2 l. C to C alkylphenol concentrations were also highly variable ranging from 5 to 1600 μg l with a median concentration of 206 μg l. These data reflect the highly variable composition of produced water discharges from different fields. The observed poor correlation of the alkylphenol isomer content and ER agonist activity suggests that other compounds present in the produced water discharges may be responsible for the ER agonist activity observed. It is recommended that further work be performed to characterise the full range of ER agonists present in offshore produced water discharges

2031 oxidoreductase

Method of identifying an anti-fungal agent which targets an essential protein or gene of a fungus comprising contacting a candidate substance with (i) a NADH:flavin oxidoreductase protein which comprises the sequence shown by SEQ ID N0:3, (ii) a NADH:flavin oxidoreductase protein which is a homologue of (i) and which comprises the sequence shown by SEQ ID NO: 8, 12, 14, 19, 24, 42, 44, 83 or 85, (iii) a protein which has 50 % identity with (i) or (ii), (iv) a protein comprising a fragment of (i), (ii) or (iii) which fragment has a length of at least 50 amino acids, (v) a polynucleotide that comprises sequence which encodes (i), (ii), (iii) or (iv), (vi) a polynucleotide comprising sequence which has at least 70 % identity with the coding sequence of (v), and determining whether the candidate substance binds or modulates (i), (ii), (iii), (iv), (v) or (vi), wherein binding or modulation of (i), (ii), (iii), (iv), (v) or (vi) indicates that the candidate substance is an anti-fungal agent

Determination of dioxin and dioxin-like compounds in sediments from UK estuaries using a bio-analytical approach: Chemical-activated luciferase expression (CALUX) assay

The DR-CALUX assay has been utilised for the bio-analytical screening of a number of estuarine sediments for dioxin-like activity. Total sediment extracts (samples containing all extracted compounds) and cleaned-up extracts (samples with the most stable compounds isolated from the total extracts) were screened. The concentration of the stable dioxin-like compounds in the cleaned-up sediment extracts was between 1.0 and 106 pgTEQg dry weight. The majority of sediments contained levels of dioxin-like compounds that were above concentrations that are considered to be a low risk to aquatic organisms. The CALUX bio-analytical approach showed some disparity with the traditional analytical approach. The reasons for these differences have been identified tentatively: firstly, the DR-CALUX assay responds to all dioxin-like compounds, and secondly, it measures non-additive effects. The dioxin-like activity of compounds in sediment total extracts, which contain both labile and stable compounds, were also assessed and were six orders of magnitude higher than the cleaned-up samples. This suggests the vast majority of the total dioxin-like activity is attributable to labile compounds. Overall, the DR-CALUX assay is shown to be a useful tool in the assessment of dioxin-like activity in estuarine sediments