Biomarkers In Environmental Assessment Research Articles

Physiological biomarkers in a resident and a non-resident estuarine teleosts species: a comparison between fish from an industrially impacted site and a non-impacted site

Physiological biomarkers were compared in two estuarine fishes: an estuarine resident (Atherinella brasiliensis) and a marine/estuarine transient (Sphoeroides testudineus). These fish were sampled from two estuarine systems: one with an active harbor (impacted site), and another which receives mostly domestic urban runoffs and is much less impacted (reference site). The resident fish displayed higher plasma osmolality and sodium (1.13 and 1.35-fold, respectively), and the transient fish displayed higher plasma osmolality (1.05-fold), potassium (1.17-fold), and magnesium levels (1.84-fold) in the impacted site, when compared to the reference site. The resident fish showed increased renal carbonic anhydrase activity and branchial expression of HSP70 (3.3-fold) in the impacted site, when compared to the reference site. Osmoregulatory parameters and HSP70 expression are strong candidates as physiological biomarkers for environmental assessment of industrial impact on estuarine teleost fishes.

The effect of shore location on biomarker expression in wild Mytilus spp. and its comparison with long line cultivated mussels

Biomarkers are a common tool in the assessment of potential effects of contaminants in aquatic organisms. In order to identify the effects of anthropogenic pollution it is essential to identify background levels and to know the range of natural variability in the biomarker response. In this study, we examined various biomarkers of stress (glutathione S-transferase and metallothionein), damage (lipid peroxidation (LPO) and DNA damage (DNA)) and reproduction (vitellin-like proteins) in marine mussels (Mytilus spp.) from four locations along a vertical transect from high to low shore and compared them with cultivated long line mussels. High shore and cultivated mussels showed significantly higher LPO and DNA damage expression than the low shore mussels indicating a level of oxidative stress resulting from mussel location. Significant effects in physiological endpoints were also found. This study highlights the need to consider the diversity of natural environmental stress factors when using biomarkers in environmental assessment.

Assessment of the mechanisms of detoxification of chemical compounds and antioxidant enzymes in the digestive gland of mussels, Mytilus galloprovincialis, from Mediterranean coastal sites

In this study the effects of the main marine pollutants (metals, PAHs, PCBs and DDTs) were assessed in native mussels from the Mediterranean coast of Spain. For this purpose several biomarkers such as benzo[a]pyrene hydroxylase (BPH), DT-diaphorase (DTD), glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPs), glutathione reductase (GR), metallothionein (MT) and lipid peroxidation (LPO) were measured in the digestive gland. Results showed increased LPO levels in mussels which accumulated high loads of organic compounds and arsenic in their tissues. BPH levels correlated to the concentrations of organic compounds in mussel tissues, though the range of BPH response was low in relation to the high gradient of accumulation of organic pollutants. Increased BPH levels, concomitant to low DTD and GST activities, were detected in mussels which presented high levels of organic pollutants in their tissues. This suggests that signs of LPO present in these organisms are related to the imbalance between phase I and phase II biotransformation processes. Furthermore, the increased levels of MT and CAT detected in mussels which showed high levels of Cd in their tissues appear to reflect a coordinated response which protects against the toxicity of this metal. The application of these biomarkers in environmental assessment is discussed.

The role of biomarkers in environmental assessment (5). Invertebrate populations and communities

Although a number of biomarkers of pollutant exposure have been identified in invertebrate species, direct linkage with changes at population and/or community levels are poorly documented and, despite the ecological importance of invertebrates, there is no conclusive evidence that individual measurements of biochemical parameters may allow the effects of pollutants on populations and communities to be predicted. Among the various biochemical parameters used as biomarkers in invertebrates exposed to pollutants in the field, only those for which changes at population or community level can be suggested are discussed in the present review. At population and community levels, the development of resistance to pesticides and changes in behaviour, reproduction and development are analysed as putative consequences of biochemical and physiological alterations. Limits to the use of biochemical parameters as biomarkers of invertebrate exposure to pollutants are discussed. Future research trends and experimental approaches to the validation of invertebrate biomarkers in environmental pollution assessment are suggested.

The role of biomarkers in environmental assessment (4). Terrestrial plants

The potential of metabolites, enzymatic processes and changes in plant performance as biomarkers in environmental assessment is reviewed. Biomarkers may be used as an early warning system of specific or general stress at each biological level, from molecules to ecosystems. The sensitivity of a species and, thus, the efficiency of a biomarker will depend on the degree of already present adaptation to environmental stress and on the homogeneity of the investigated population. Biomarkers for specific environmental stresses are scarce; better known are biomarkers for environmental stress complexes such as heavy metals, physiological drought and extreme temperature or biomarkers as a reaction on a full scale of environmental stresses. It is argued that a battery of biomarkers is necessary to evaluate chemical hazards to species.

The role of biomarkers in environmental assessment (1). Introduction

A series of four papers, commissioned by the European Science Foundation, are presented on the state-of-the-art of the use of biomarkers in environmental assessment. These papers are phylogenetically based and cover invertebrates, vertebrates, plants and invertebrate populations and communities.

The role of biomarkers in environmental assessment (3). Vertebrates

The most compelling reason for using biomarkers is that they can give information on the effect of pollutants rather than mere quantification of the levels present. The most critical aspect of environmental assessment is for society to decide how much damage it is prepared to tolerate. Once this is decided it is possible to devise tests to enforce these decisions. Suites of biomarkers have the potential to play an important role in environmental assessment.

The role of biomarkers in environmental assessment (2). Invertebrates

The potential use of biomarkers in ecological risk assessment is explored. The biomarker concept, initially developed to form a basis for studies at the individual/population level, is extended to include community and ecosystem level studies. A strategy is outlined in which biomarkers might be used to assess chemical exposureand the cumulative, adverse effects of toxicants on biotain situ. Protocols for identifying communities, species and populations most at risk are described. The role of biomarkers in the evaluation of the effectiveness of remedial action to alleviate pollution is discussed. It is proposed that, in addition to biomarker measurements on samples obtained from organisms at field sites, biomarker screening tests should be initiated in the laboratory with a range of new chemicals and organisms relevant to the field sites thought to be at risk. This will help to establish links between laboratory-based testing and adverse effectsin situ.