Determination of metal and organometal trophic bioaccumulation in the benthic macrofauna of the Adour estuary coastal zone (SW France, Bay of Biscay) (original) (raw)
Related papers
1996
Biological monitoring techniques, selected to cover mcreasing levels of biological organisation (cellular, individual, population and community), were compared and contrasted to determine the relative sensitivities of these approaches to heavy metal contammation. The study was centred on the Fal Estuary m Cornwall, an ideal experimental field site-with well documented heavy metal contamination resulting firom the long-term discharge of waste from a local tin mine. Five creeks leadmg fi-om the estuary diEfer dramatically in the concentrations of heavy metals in the sedunents, but little in natural envuronmental variables (sedunent granulometry, salinity etc.). The contaminant mduced damage was evaluated at the cellular level m Mytilus edulis by the Neutral Red Assay to detect lysosomal membrane damage. Parameters of the energy budget of this species were determined to estmiate 'Scope for Growth' of mdividuals. along with a Larval Survival assay to estabUsh their reproductive and developmental success. At the population level. Cohort Growth studies were undertaken using the polychaete Nephtys hombergi. At the community level, data firom an extensive three year survey of benthic macrofauna structure were analysed. In addition to investigating biological parameters, contammant levels in sedunent and tissue were determuied using Atomic Absorption Spectrommetry. All techniques, except the population level, detected the extreme pollution of the most contaminated creek, Restronguet, but did not accurately reflect the known metal gradient. However, community studies established distinct macrofaunal assemblages between both sites and years. Techniques were compared and validated in a novel approach using the program BIOENV, with the multivariate analysis package PRIMER (Plymouth Routines in Multivariate Ecological Research). The cellular assay correlated reasonably well agamst the heavy metal levels, the larval survival assay correlated well to the community structure. However, the conimunity structure approach was the most sensitive and relevant monitoring method to determme the long-term contamination of the Fal Estuary. iii Contents Copyright Statement ; ; i-TitlePage ; I.. ". ii Abstract iii Contents iv List of Tables. ^ ix List of Figures x Abbreviations : xi Acknowledgement , xii Author's Declaration... .' • •• xiii 33 Escherichia coli. 33 RESULTS 34 Sediment metal analysis 34 Mussel {Mytilus edulis) metal analyses 37 Environmental variables ..•••39 Sediment grain size and organic matter. 39 Pore water salinity and pH. , 41 Bacteriology of estuary water 43 iv Mussel Mortality , CONCLUSIONS , : ; 45 CHAPTERS ,. , 46 Community Structure Analysis ••..46 Sampling 54 Sample processing and laboratory analysis , ^ • 55 Analyses of community structure data .' 56 Univariate Analysis Multivariate Analysis Dendrograms and MDS (Multi-dimensional scaling) plots 58 Analysis at varying levels of taxonomic organisation 59 Analyses of environmental variables : 59 Linking the faunistic data to the enviromnental data 59 RESULTS-Enviroimiental variables • Community Structure: 62 Univariate measures ; Multivariate analyses 67 Single year data • 67 Relating commimity to environment , 70 Discrimination between sites on basis of the organisms present 75 Taxonomic levels and discrimination of creeks 81 Time series data 1991-1993 83 DISCUSSION Observations of and comments on the community structure of the creeks 86 Adaption and tolerance 86 Lifehistory strategy. Sediment characteristics 88 Observations of and comments on the temporal change in community structure....... 89 Species patterns 89 Contaminant-induced effects? Natural changes? ^ •-91 Decreased predation? Overview of the community structure analysis technique-Relative sensitivities of univariate and multivariate techniques CONCLUSION CHAPTER 4 Population Size Structure Studies: Nephtys hombergi •••-95 INTRODUCTION General introduction Underlying principles Methods of age determination by size structure analysis 97 Direct observation of individuals 97 Growth marks 97 Tagging Inference from population structure 98 Previous size frequency studies 100 Test organism: Nephtys hombergi 100 Aims MATERIALS AND METHODS ' 102 Species choice 102 Sampling Measurements V 109 Factors which could affect the growth and size of Nephtys hombergi Abiotic factors Biotic factors : HO Criticisms of and difficulties with the technique Ill CONCLUSION 113 Scope For Growth: Physiological Energetics Of Mytilus edulis Ecological relevance 139 CONCLUSION. CHAPTER 6 Larval Bidassay: Growth And Survival Of Mytilus edulis Larvae 141 INTRODUCTION Bioassays Rearing mussel larvae 143 Spawning and life-history ••• 144 The larval survival bioassay 146 Aims MATERIALS AND METHODS. 147 Sampling Larval culture Bioassay RESULTS Larval viability Survival DISCUSSION Summary ; .- .
Bioaccumulation of heavy metals by the flora and benthic macrofauna of the Bouregreg estuary wetland
MATEC Web of Conferences, 2018
Estuarine systems account for a high proportion of wetlands in Morocco due to the development of the river system. These estuarine and coastal Moroccan environments are as rich in fauna and flora as their European equivalents and present much originality. However, these coastal areas are generally highly urbanized and industrialized, and therefore subject to domestic and industrial discharges. The Bouregreg Estuary represents a good example of this situation, in view of this pollution (organic, chemical and biological) and the absence of fresh water supply upstream of the estuary after the dam was built, is increasingly unable of restoring the equilibrium of this ecosystem. This tide can instead ensure the polluting discharge downstream or upstream. Metallic contamination affects the different compartments of the estuarine ecosystem (sediment, water) and benthic species (fauna and flora). The objective of this study is to assess the accumulation and bioaccumulation of five heavy metals (Cu, Fe, Zn, Cr and Pb) at the sediment level of two dominant plant species (Artiplex portulacoides and Sarcocornia fructicosa) and three species of benthic macrofauna (Scrobicularia plana, Venerupis decussata and Hediste diversicolor) from the wetland of this estuary. This work will enable us to clearly understand the nutritional relationships between plant, animal, water and sediment species. The results of the analysis revealed that bioaccumulation varies from one species to another and from one metal to another. Thus, the levels of Lead and Chromium at Sarcocornia fructicosa are higher than those found at Artiplex portulacoides. Nevertheless, the latter accumulates better the other metals: Cu, Zn and Fe. While, the macrofauna shows a fairly large variation depending on the life style and sensitivity of species. Thus, Hediste diversicolor showed high levels of the various metals analyzed compared to Scrobicularia plana and Venerupis decussata.
The effects of metal contamination on estuarine macrobenthic communities were investigated using the Biological Traits Analysis (BTA). The study was carried out in the Tagus estuary (western Portugal). Samples of macrobenthic communities and associated environmental variables were taken in four surveys (September 2012, and February, May and October 2013) across the contamination gradient from three main zones: a slightly contaminated, a moderately contaminated and a highly contaminated zone. Functional traits for the most abundant species were assigned using seven categories based on "Feeding mode", "Life span", "Body size", "Motility", "Position in sediments", "Larval type" and "AMBI ecological group". To investigate whether the macroinvertebrate community structure was associated with the environmental parameters and biological traits an integrative multivariate analysis, combining the RLQ analysis and the fourth-corner method, was applied. Within this analysis, human-induced estuarine variables (metals) were rendered independent from natural ones (sediment fine particles) through partial correlations. Following this approach, it was possible to decouple the effects of two typically highly correlated environmental descriptors with different origins. Overall, the study identified significant relationships between sediment environmental descriptors and the functional traits of macrobenthic communities. Further, RLQ/Fourth-corner combined analysis successfully isolated the traits and corresponding species that were most correlated with the measured concentration of trace metals in sediments, supporting the knowledge that benthic organisms exhibit distinct responses to different levels of disturbance. A shift in species dominance occurred along the contamination gradient with epifaunal tolerant species with very small size, long life span, and crawling motility dominating the highest contaminated area. This area was also related with surface deposit-feeder species. The most representative species associated with this area was the gastropod Peringia ulvae. Less contaminated sites revealed large-sized specimens, carnivores and swimmers, mainly represented by the polychaete Nephtys hombergii. This finding is consistent with other studies addressing different kinds of disturbance, where a shift in dominance from carnivore/predators, long-lived and large animals to the predominance of small-size, short-lived and deposit-feeders has been observed across increasing gradients of disturbance. Our results reinforce the importance of macrobenthic functional traits analysis to assess human disturbances driven impacts in multi-stressed estuarine ecosystems. By analysing the environmental variables with different origins independently, we were able to draw conclusions about the effects of human pressures (metals) on macrobenthic traits. Such distinction can be particularly useful to isolate different environmental descriptors and assess their effects on functional diversity, making the current approach promising in evaluation the ecological effects of anthropogenic stressors in estuarine areas.
Journal of Soils and Sediments, 2013
Purpose The purpose of this paper is to compare three approaches for providing information on the bioaccumulation potential of metals from contaminated sediments to the deposit-feeding polychaete Arenicola marina. Materials and methods We present metal (Ag, As, Cd, Cu, Pb and Zn) bioaccumulation results from field-collected sediments quantified through direct measurements of bioaccumulated concentrations in A. marina over a period of 30 days under controlled laboratory exposures and compare these results with bioaccumulated metal concentrations in field-collected organisms from the same sites of collection of the sediments used in the laboratory exposures. For the metals for which model parameters are available (Ag, As, Cd and Zn), we also compare these results with biodynamic model predictions. We considered three UK estuaries characterised by a well-reported history of trace metal contamination and bioavailability in addition to the (control) site of collection of the worms. Results and discussion The results from laboratory-exposed organisms showed that the standard 28-day exposure duration may be adequate to identify the potential for metal bioaccumulation in this polychaete at the sites considered here. However, the time course of bioaccumulated concentrations and the comparison with measured concentrations in field-collected worms show that a steady state has not been reached, confirming the need for extended exposure periods. The worms showed symptoms of stress in feeding and growth during the initial 10 days of exposure and subsequent partial recovery during the following 20 days, suggesting that stress was not always caused by sediment contamination but that it was likely associated with handling and acclimation. At this last stage of the exposure, a generalised biodynamic model was used to provide estimates of bioaccumulated metal concentrations and net accumulation rates in worms.
Science of The Total Environment, 2008
Two food webs from the Mar Menor coastal lagoon, differing in the distance from the desert-stream through which mining wastes were discharged, were examined by reference to essential (Zn and Cu) and non-essential (Pb and Cd) metal concentrations and stable isotopes content (C and N). The partial extraction technique applied, which reflects the availability of metals to organisms after sediment ingestion, showed higher bioavailable metal concentrations in sediments from the station influenced by the mining discharges, in agreement with the higher metal concentrations observed in organisms, which in many cases exceeded the regulatory limits established in Spanish legislation concerning seafood. Spatial differences in essential metal concentrations in the fauna suggest that several organisms are exposed to metal levels above their regulation capacity. Differences in isotopic composition were found between both food webs, the wadi-influenced station showing higher δ15N values and lower δ13C levels, due to the discharge of urban waste waters and by the entrance of freshwater and allochthonous marsh plants. The linear-regressions between trophic levels (as indicated by δ15N) and the metal content indicated that biomagnification does not occur. In the case of invertebrates, since the “handle strategy” of the species and the physiological requirements of the organisms, among other factors, determine the final concentration of a specific element, no clear relationships between trophic level and the metal content are to be expected. For their part, fish communities did not show clear patterns in the case of any of the analyzed metals, probably because most fish species have similar metal requirements, and because biological factors also intervened. Finally, since the study deals with metals, assumptions concerning trophic transfer factors calculation may not be suitable since the metal burden originates not only from the prey but also from adsorption over the body surfaces and seawater ingestion.
2005
The Mar Menor coastal lagoon is one of the largest of the Mediterranean Sea. Ancient mining activities in the mountains near its southern basin have resulted in metal contamination in the sediment. The metal bioavailability of these sediments was determined through laboratory toxicity bioassays using three Mediterranean sea urchin species and two amphipod species, and by means of field bioaccumulation measurements involving the seagrass Cymodocea nodosa. The effect of sediment metal contamination on benthic communities was assessed through benthic infaunal analyses, applying classical descriptive parameters and multivariate techniques. The sediments affected by the mining activities presented high levels of toxicity and metals were also accumulated in the seagrass tissues, pointing to metal bioavailability. Although the classical benthic indices were not clear indicators of disturbance, the multivariate techniques applied provided more consistent conclusions.
Water Research, 1984
Sediments and an indicator organism (Macoma balthica, a deposit-feeding bivalve) were used to assess the relative importance of secondary sewage, urban runoff, a landfill containing metal-enriched ash wastes and a yacht harbor in contributing to Ag, Cu and Zn enrichment in South San Francisco Bay. Spatial gradients in sediments and organisms showed Cu and Ag enrichment originated from sewage discharge, whereas Zn enrichment originated from both sewage and urban runoff. Elevated concentrations of Cu in the sediments of the yacht harbor resulted from a high abundance of fine particles. The biological availability of Cu, Ag and Zn did not coincide with metal enrichment in sediments. The availability of Cu and Ag was greatest nearest the sewage outfall and greater in winter and spring than in summer. The availability of Zn in urban runoff appeared to be lower than the availability of Zn associated with sewage.
Laboratory-based bioaccumulation and toxicity bioassays are frequently used to predict the ecological risk of contaminated sediments in the field. This study investigates the bioassay conditions most relevant to achieving environmentally relevant field exposures. An identical series of metal-contaminated marine sediments were deployed in the field and laboratory over 31 days. Changes in metal concentrations and partitioning in both sediments and waters were used to interpret differences in metal exposure and bioaccumulation to the benthic bivalve Tellina deltoidalis. Loss of resuspended sediments and deposition of suspended particulate matter from the overlying water resulted in the concentrations of Cu, Pb and Zn (major contaminants) becoming lower in the 1-cm surface layer of field-deployed sediments. Lower exchange rates of overlying waters in the laboratory resulted in higher dissolved metal exposures. The prediction of metal bioaccumulation by the bivalves in field and laboratory was improved by considering the metal partitioning within the surface sediments.