A schematic sampling protocol for contaminant monitoring in raptors.

Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility. The present perspective introduces a schematic sampling protocol for contaminant monitoring in raptors. We provide guidance on sample collection with a view to increasing sampling capacity across countries, ensuring appropriate quality of samples and facilitating harmonization of procedures to maximize the reliability, comparability and interoperability of data. The here presented protocol can be used by professionals and volunteers as a standard guide to ensure harmonised sampling methods for contaminant monitoring in raptors.

Pesticide residues in sediments and aquatic species in Lake Nokoué and Cotonou Lagoon in the Republic of Bénin.

Lake Nokoué and Cotonou Lagoon are the most important and most productive continental freshwaters in Bénin, with an estimated fish production of over 2 tonnes per hectare in Lake Nokoué. Organochlorine pesticides are used in agriculture and to repel tsetse flies, malaria mosquitoes and other diseases raised. Sediment, fish, shrimp and oyster species were collected in Lake Nokoué and Cotonou Lagoon for pesticide residues analysis. The main pesticides identified in sediment were pp'-DDT and its metabolites pp-DDE and pp'-DDD, with residue levels between the detection limit and 24.4 µg/kg dry weight. Fish species commonly consumed such as Elops lacerta, Podamasys jubelini, Gobbienellus occidentalis, Ethmalosa fimbriata, Mugil cephalus and Hemichromis fasciatus were contaminated with residues of seven to nine pesticides, including pp-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, α-endosulfan, aldrin, dieldrin and γ-hexachlorocyclohexane. The levels ranged from detection limit to 289 ng/g lipid. The same pesticides were also detected in other aquatic species, such as shrimp and oysters. A summed risk assessment, comparing pesticide intake levels through fish consumption with tolerable daily intake levels proposed by the World Health Organization, showed in all cases a low risk for human health.

Health risks associated with pesticide residues in sediments, fish, and plants from the Ouémé Valley in the Republic of Bénin.

To determine possible human and environmental health risks, organochlorine pesticide residues were determined in vegetables grown in floodplains along the Ouémé River near Lowé in Bénin. Testing of vegetables found 13 pesticides with ΣDDT, α-endosulfan, Σdrin, and lindane being most important. The same pesticides were also detected in plants eaten by bovine cattle, sheep, and herbivorous fish. Human pesticide intake by vegetable consumption was compared with tolerable daily intake (TDI) values reported by the World Health Organization. Pesticide intake by fish consumption was estimated from residue levels in whole fish collected from the Ouémé River in 2004 and reported earlier. Fish consumption does not pose a risk for human health, but consuming vegetables that contain pesticide residues may lead to exceedance of TDI values. Based on these findings, concerns are warranted, and more work is needed to understand the full exposure profile for the local population.

PCB and organochlorine pesticide concentrations in eel increase after frying.

In several countries such as the Netherlands, consumption of eel from polluted waters is not allowed because the concentrations of polychlorinated biphenyls (PCBs) exceed official tolerance limits. Few experiments have been carried out to assess if pre-treatment, such as cooking and frying would alter the PCB concentrations and maybe bring them under the tolerance limits. We have carried out a frying and cooking experiment, which has shown that the concentrations of PCBs and organochlorine pesticides (OCPs) increase in eel after frying. The effect of boiling is negligible. This shows that preparation methods for eel as food product do not help in bringing PCB and OCP concentrations down to safe values.

Hepatic retinoid levels in seven fish species (teleosts) from a tropical coastal lagoon receiving effluents from iron-ore mining and processing.

The present study was undertaken to investigate the possible effects of Fe and trace element exposure on hepatic levels of retinoids in seven fish species. Concentrations of retinoids were measured in fish collected from a coastal lagoon in Brazil that receives effluents from an iron-ore mining and processing plant. Fish from nearby coastal lagoons were also included to assess possible differences related to chemical exposure. Results indicated considerable differences in hepatic retinoid composition among the various species investigated. The most striking differences were in retinol and derivative-specific profiles and in didehydro retinol and derivative-specific profiles. The Perciformes species Geophagus brasiliensis, Tilapia rendalli, Mugil liza, and Cichla ocellaris and the Characiforme Hoplias malabaricus were characterized as retinol and derivative-specific, while the Siluriformes species Hoplosternum littorale and Rhamdia quelen were didehydro retinol and derivative-specific fish species. A negative association was observed between Al, Pb, As, and Cd and hepatic didehydro retinoid levels. Fish with higher levels of hepatic Fe, Cu, and Zn showed unexpectedly significant positive correlations with increased hepatic retinol levels. This finding, associated with the positive relationships between retinol and retinyl palmitate with lipid peroxidation, may suggest that vitamin A is mobilized from other tissues to increase hepatic antioxidant levels for protection against oxidative damage. These data show significant but dissimilar associations between trace element exposure and hepatic retinoid levels in fish species exposed to iron-ore mining and processing effluents, without apparent major impacts on fish health and condition.

Characterizing field sediments from three European river basins with special emphasis on endocrine effects - A recommendation for Potamopyrgus antipodarum as test organism.

The assessment of endocrine disrupting potentials of field sediments has until now been mostly limited to classical chemical analysis, in vitro assays and in vivo bioassays performed with vertebrates. There is an urgent need for easy, cheap and reproducible invertebrate tests which may be applied in certain monitoring activities. Since the mudsnail Potamopyrgus antipodarum is known to be tolerant to natural stressors, but also sensitive to endocrine disrupting chemicals, it is very likely that this organism could be suitable for the assessment of endocrine effects of e.g. field sediments. Within this study the endocrine potential of sediments in three European river basins was assessed. The yeast estrogen screen (YES) and a sediment contact test with P. antipodarum were performed. Furthermore, analyses of physico-chemical properties and concentrations of heavy metals, PAHs, organotins, natural steroids and alkylphenols were done. In the sediment contact test, the reproduction of the snail was promoted by a part of the sediments. This phenomenon could not be explained by their physico-chemical properties. However, at some of those sites a high estrogenic activity was detected in the YES, leading to the assumption that endocrine disrupting compounds could be responsible for those effects. This assumption could be confirmed to some extent with partially high concentrations of xeno-estrogens (e.g. nonylphenol) at the certain sites. Our study demonstrates the applicability of the test with P. antipodarum for a variety of sediments and once again points out the need of suitable in vivo biotests for the risk assessment of field sediments.

Exposure modeling on a river basin scale in support of risk assessment for chemicals in European river basins.

Following the 2000 European Water Framework Directive and recent insights into sediment management on a river basin scale, we discuss in this paper an exposure model aiming to support a risk assessment for chemicals on a basin-wide scale. It establishes spatial relations between causes (pollution sources) and effects (ecological risk), taking into account the geometry, hydrology, and fine sediment dynamics of European river basins. The model, called EXPOBASIN, explicitly takes into account the interaction of chemicals with fine sediment particles, which is important for many policy-relevant chemicals, such as trace metals and polycyclic aromatic hydrocarbons, and it addresses the potential release of historically polluted sediments as a result of extreme floods, which is a major concern in different European river basins. Bioavailability and bioaccumulation are included in the assessment. As a result, the exposure can be quantified not only in terms of water concentrations, but also in terms of sediment concentrations and concentrations in biota. The primary question to be answered by EXPOBASIN is how chemicals, pollution sources, or both rank quantitatively and objectively on a basin-wide scale. Near the end of 2009, the tool will become available to all European water managers and their technical advisors, as a result of the European Union 6th Framework Programme project MODELKEY. The calibration and validation of EXPOBASIN has only just started and will be completed in 2008/2009. Applications to 3 case study areas are planned in this respect. This paper presents the key building blocks of EXPOBASIN and shows some sample results illustrating the raking of pollution sources and chemicals. At the end of the paper, some perspectives for future developments are outlined.

Assessing the risks of persistent organic pollutants to top predators: a review of approaches.

Accurate risk assessment of secondary poisoning by persistent organic pollutants (POPs) in top predators is possible but requires multidisciplinary input from wildlife ecology, ecotoxicology, and analytical chemistry. Because of the transfer of POPs up the food chain, traditional approaches to exposure assessment based on POPs in abiotic compartments or organisms low in the food chain can make the assessment of risk to top predators complicated. For more direct, accurate, and site-specific methods of assessing the risks of secondary poisoning of top predator by POPs, we classify 2 main approaches: diet based and tissue based. Exposure assessment via the diet-based approach requires samples of the predator's diet and measured concentrations in the prey items, realistic estimates of dietary composition, and ingestion rates. The even more direct, tissue-based approach uses measured POP concentrations in tissues of top predators to determine internal exposure coupled with tissue-based effect concentrations (or biological responses measured via biomarkers) to determine risk. The advantage of these methods is that uncertain estimates of POPs transfer to top predators from lower trophic levels are avoided. In practice, the availability of dose-response data and internal exposure-response relationships for POPs in top predators is limited, so these may have to be extrapolated from surrogate species. In this paper we illustrate and evaluate the potential of diet-based and tissue-based risk assessment approaches with case studies and demonstrate that appropriate methodologies significantly reduce the uncertainty in risk assessments of POPs.

Organochlorine and organophosphorous pesticide residues in the Ouémé River catchment in the Republic of Bénin.

The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.

Contamination of fish by organochlorine pesticide residues in the Ouémé River catchment in the Republic of Bénin.

In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.

Monitoring and evaluation of the environmental dissipation of the marine antifoulant 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) in a Danish Harbor.

The concentration of marine antifoulant 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT; the active ingredient in Sea-Nine 211 Antifouling Agent) leaching into a Danish Harbor from two painted ships was quantitated at varying distances from the ships. Sediment and suspended particulate matter were also analyzed for DCOIT. Water samples were concentrated on-site using C-18 solid phase extraction and subsequently analyzed by gas chromatography-tandem mass spectrometry. A strong decline in DCOIT water concentration as a function of distance from the ships was observed. The highest concentration (maximum 283 ng/l) was measured in the immediate vicinity of the ships and the concentration declined rapidly to less than the limit of detection (5 ng/l) at 400 m from the ships' surfaces. The measured decline curve was compared to that calculated using a one-dimensional model (ECoS). The comparison indicates that the primary mechanism of dissipation of DCOIT is not dilution resulting from dispersion but degradation with a rate constant in the order of 1 h(-1). Thus the field results correlate with the earlier microcosm studies demonstrating that DCOIT biodegrades rapidly in a marine environment.

Copper toxicity in relation to surface water-dissolved organic matter: biological effects to Daphnia magna.

Water quality standards for copper are usually stated in total element concentrations. It is known, however, that a major part of the copper can be bound in complexes that are biologically not available. Natural organic matter, such as humic and fulvic acids, are strong complexing agents that may affect the bioavailable copper (Cu2+) concentration. The aim of this study was to quantify the relation between the concentration of dissolved natural organic matter and free Cu2+ in surface waters, and the biological effect, as measured in a standardized ecotoxicological test (48 h-median effective concentration [EC50] Daphnia magna, mobility). Six typical Dutch surface waters and an artificial water, ranging from 0.1 to 22 mg/L dissolved organic carbon (DOC), were collected and analyzed quarterly. Chemical speciation modeling was used as supporting evidence to assess bioavailability. The results show clear evidence of a linear relation between the concentration of dissolved organic carbon (in milligrams DOC/L) and the ecotoxicological effect (as effect concentration, EC50, expressed as micrograms Cu/L): 48-h EC50 (Daphnia, mobility) = 17.2 x DOC + 30.2 (r2 = 0.80, n = 22). Except for a brook with atypical water quality characteristics, no differences were observed among water type or season. When ultraviolet (UV)-absorption (380 nm) was used to characterize the dissolved organic carbon, a linear correlation was found as well. The importance of the free copper concentration was demonstrated by speciation calculations: In humic-rich waters the free Cu2+ concentration was estimated at approximately 10(-11) M, whereas in medium to low dissolved organic carbon waters the [Cu2+] was approximately 10(-10) M. Speciation calculations performed for copper concentrations at the effective concentration level (where the biological effect is considered the same) resulted in very similar free copper concentrations (approximately 10(-8) M Cu) in these surface waters with different characteristics. These observations consistently show that the presence of organic matter decreases the bioavailability, uptake, and ecotoxicity of copper in the aquatic environment. It demonstrates that the DOC content must be included in site-specific environmental risk assessment for trace metals (at least for copper). It is the quantification of the effects described that allows policy makers to review the criteria for copper in surface waters.

Imposex and organotin concentrations in Buccinum undatum and Neptunea antiqua from the North Sea: relationship to shipping density and hydrographical conditions.

The presence and the development of imposex were investigated in the common whelk (Buccinum undatum) and the red whelk (Neptunea antiqua) from the open North Sea and the Skagerrak. Imposex development was related to levels of organotins in snails and in the fine fractions (< 63 microm) of the sediments they inhabit. The sampling locations were classified according to three levels of traffic densities of ships of > or = 100 gt per day passing within 15 Nautical miles of the sampling station, shipping levels being: high (> 10 ships day(-1)), intermediate (5--10 ships day(-1)), and low (< 5 ships day(-1)). Sampling stations were also classified according to presence or absence of a vertically stratified water column. In the snails the body levels of the butyltin metabolites MBT and DBT and the parent phenyltin compound TPT, were higher than those of TBT and PT metabolites. In the sediment, the parent compounds and the mono-substituted metabolites MBT and MPT were present in the highest concentrations. The highest body levels of all organotin compounds and the highest imposex indices for the common whelk were found at those locations in the Southern Bight and the German Bight that had a high shipping density as well as a homogeneously mixed water column during the whole year. At these locations sediment levels of organotins were also higher than at other sites. In contrast, the body levels of organotins were low and imposex was sometimes even completely absent in snails from stratified deep-water stations in the Skagerrak, despite a very high shipping density in the entrance area of the Baltic. In sediments from stratified locations with low or intermediate shipping densities, organotin compounds were below or close to their respective limits of detection. These stations were located in areas with a stratified water column during the whole year. The results can be explained by postulating a much higher resistance for dissolved organotins to migrate through a pycnocline. Organotins could only transgress through a pycnocline when adsorbed to settling particles that manage to transgress the boundary between layers. N. antiqua could only be obtained in sufficient numbers from deeper water stations, which almost all had a stratified water column. At stations where both snail species were obtained and imposex was present, the imposex index was higher in the red whelk. Hence N. antiqua seems to be the more sensitive species of the two. In the red whelk, imposex development increased with shipping density too, though in the smaller samples the trend was not significant. Average biota-sediment accumulation factors (BSAFs; normalised for lipid content in snails and TOC content in the fraction < 63 microm in sediments) for Buccinum ranged from 0.4 to 1.0 for butyltins and were similar to literature values reported for TBT in other marine species. Higher average BSAF values were found for phenyltins 1.5 (MPT) to 17 (TPT). The high values for TPT match the ranges expected from equilibrium partitioning concepts of persistent hydrophobic compounds. The ratio of live snails to the total number of live snails plus empty shells ranged between 2.5 and 93%. This parameter might be a useful indicator to compare past and present densities of populations of both species in different areas of the North Sea.

Pyrene biotransformation products as biomarkers of polycyclic aromatic hydrocarbon exposure in terrestrial Isopoda: concentration-response relationship, and field study in a contaminated forest.

In this study, biotransformation products of pyrene were measured in the hepatopancreas of terrestrial isopods as biomarkers of polycyclic aromatic hydrocarbon (PAH) exposure. These products--pyrene-1-glucoside, pyrene-1-sulfate, an unknown pyrene conjugate, and 1-hydroxypyrene--were quantitated using high-performance liquid chromatography (HPLC) with fluorescence detection. In a controlled exposure experiment, a linear relationship was established between pyrene exposure and pyrene metabolite concentrations in the hepatopancreas of Porcellio scaber Latr. To this end, isopods of the species P. scaber were exposed to a range of pyrene concentrations spiked to their food. A linear response was found for all pyrene conjugates in the range 0.67 to 67 microg/g of pyrene (dry wt). Hepatopancreatic pyrene metabolite concentrations were also measured in isopods (P. scaber and Oniscus asellus L.) from PAH-contaminated field sites. The sites and the inhabiting isopods were located in a gradient of atmospheric PAH deposition caused by a nearby blast furnace plant. The highest levels of conjugated 1-hydroxypyrene in the hepatopancreas were 3.8 pmol/g fresh weight (pyrene-1-glucoside) and 2.8 pmol/g fresh weight (pyrene-1-sulfate) (expressed on whole-body basis). The levels of the pyrene metabolites correlate with reported pyrene concentrations in spite of these sites. As pyrene is one of the most predominant PAHs, analysis of its metabolites provides a good tool for environmental risk assessment of ecosystems with regard to PAH exposure, bioavailability, and biotransformation.

Imposex induction in laboratory reared juvenile Buccinum undatum by tributyltin (TBT).

Here we report a series of experiments on the development and occurrence of imposex in the common whelk, Buccinum undatum, under the influence of (chronic) exposure to butyltin compounds. The main objective of the experiments was to obtain more information about the effects of organotin compounds in the marine environment, which possibly relate to the reported decline of B. undatum in Dutch coastal waters. In these studies tributyltin (TBT) dose-dependently induced the development of male sexual organs in juvenile whelks. A TBT concentration >7 ng Sn/l induced imposex in juvenile whelks. Growth in TBT-exposed juvenile whelks was significantly reduced compared to the reference group at a nominal TBT dose ≥ 4 ng Sn/l in one of the exposure studies. After 5 years in the laboratory, egg-laying was only observed in reference aquaria. Thus, TBT might impair whelk reproduction through growth reduction. The results showed a sensitivity towards imposex development in different life-stages. Juveniles were the most sensitive, adolescent females also responded, but adult females did not respond to TBT exposure, although they dose-dependently increased their organotin (OT) body-burden when exposed. Environmental TBT during only the in ovo stage, did not result in an increased masculinisation compared to non-exposed developing whelks. Histological studies showed no sterilisation due to mechanical blockage of the (adult) female genital opening by sperm-duct tissue. Gonadal development in 2-year old juveniles was not observed. This implies that the differentiation of a penis and a vas deferens, which already occurred in the first few months after hatching, was not controlled by gonadal factors. No other sexual characteristics than those already visible with the eye were found. TBT inactivated CYP450 to its inactive form CYP420 in in vitro exposure studies with microsomal fractions of whelks. The studies have shown TBT to disrupt sexual development dose dependently in juvenile common whelks. TBT also dose dependently exerts an effect on enzymatic (CYP450) processes. Although no mechanical sterilisation was observed, reproduction might be impaired through growth reduction.

Bioaccumulation and toxicity of tributyltin to a burrowing heart urchin and an amphipod in spiked, silty marine sediments.

The presence of tributyltin (TBT) in silty sediments is regarded as a long-term threat to marine and estuarine environments due to its persistence. The bioaccumulation kinetics and toxicity of TBT in the deposit-feeding heart urchin Echinocardium cordatum was studied in silty sediment spiked with TBT and equilibrated prior to the 28-d exposure. An additional 10-d acute toxicity test was carried out with the burrowing amphipod Corophium volutator in the same sediment. Because E. cordatum has a low lipid content and apparently high elimination and metabolic rates, only a moderate degree of TBT bioaccumulation was observed, with biota-sediment accumulation factors (BASFs) of 0.09 to 0.21 (dry weight basis) and biota accumulation factors (BAFs) of 180 to 843 (wet weight basis). The lethal body residue in E. cordatum (soft tissue and skeleton) was 0.8 to 3.4 nmol TBT+ /g wet weight which, considering the differences in lipid content, is comparable to data on other taxonomic groups. For E. cordatum and C. volutator, the LC50s for pore water (222 and 329 ng Sn/L) were also close to reported values for aquatic and benthic organisms. The TBT concentrations in the pore water of the silty sediment were much lower than might be expected from the octanol-water partition coefficient. The measured sediment-water partitioning coefficient Kp was 8,700 L/kg dry weight. Consequently, toxicity was observed at a relatively high TBT concentration in the bulk sediment with LC50s for E. cordatum and C. volutator of 1,594 and 2,185 ng Sn/g dry weight, respectively. The results show that TBT is highly toxic to the benthic species investigated and sorption in the silty sediment strongly reduced the bioavailability of the compound.