References of "Richir, Jonathan"
     in
Bookmark and Share    
Full Text
See detailEffets anthropiques sur les écosystèmes marins
Richir, Jonathan ULg; Grosjean, Philippe

Scientific conference (2016, January 28)

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailSTAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts: The STARECAPMED project
Richir, Jonathan ULg; Abadie, Arnaud ULg; Binard, Marc ULg et al

Conference (2015, November 08)

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean ... [more ▼]

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean littoral. The station, established in 1970, has archived environmental data for decades. The STARECAPMED project, multidisciplinary, articulates itself around these two main features. Its objective is to understand how human activities can interact with the fundamental processes that govern the functioning of the different coastal ecosystems of a Mediterranean bay. The understanding of these interactions involves: (i) the identification of the anthropogenic pressures; (ii) the quantification of their impacts on the ecosystems; (iii) the prioritization of these impacts. STARECAPMED also aims to confirm the relevance of the use of the Calvi Bay as a reference in the study of local and global pressures and the changes they may cause on the structure and the functioning of Mediterranean coastal ecosytems. [less ▲]

Detailed reference viewed: 44 (9 ULg)
Full Text
Peer Reviewed
See detail) The spatial variability of trace element bioaccumulation processes: Tools to environmental management
Richir, Jonathan ULg; Lejeune, Lejeune; Lepoint, Gilles ULg et al

Conference (2015, November 07)

As transitional environments, coastal meadows are particularly vulnerable to pollution. Trace elements remain contaminants of concern because of their persistence, their ability to accumulate in biota and ... [more ▼]

As transitional environments, coastal meadows are particularly vulnerable to pollution. Trace elements remain contaminants of concern because of their persistence, their ability to accumulate in biota and their toxicity. Local, regional, national and cross-border programs are thus initiated to monitor their environmental occurrence. Sentinel organisms, or bioindicators, have been widely used to this end since they accumulate the bioavailable and thus potentially toxic fraction of contaminants. In the framework of the STARECAPMED project, the accumulation of trace elements in the seagrass Posidonia oceanica (L.) Delile was studied at different spatial scales: along a radial (100 m scale), in a bay (1 km scale), along the French Mediterranean littoral (10-100 km scale) and along the whole Mediterranean coastline (100-1000 km scale). Results showed that the contamination of the sampled shoots could vary as much at opposite scales. This benthic primary producer accumulates contaminants sequestered in the sediments, in addition to their dissolved fraction in the water column. The sediments also offer a time integration of coastal pollution and thus amplify the pollution signal recorded by the seagrass, resulting in the observed spatial variability. These results demonstrate that the in-depth knowledge of the ecology of the monitored bioindicator and the interactions it shares with its environment cannot be ignored. Such failure could lead to erroneous interpretations of the levels of contamination of monitored sites, and points out the need to define a sampling strategy based on the monitoring objectives and the selected bioindicator. [less ▲]

Detailed reference viewed: 35 (2 ULg)
Full Text
Peer Reviewed
See detailThe trace element contamination of coastal waters: A holistic approach to environmental monitoring surveys
Richir, Jonathan ULg; Gobert, Sylvie ULg

Conference (2015, November 07)

Sustained monitoring programs are necessary to evidence the efficacy of regulatory controls on pollutant discharges and to assess the health status of ecosystems. Within this perspective, this study aimed ... [more ▼]

Sustained monitoring programs are necessary to evidence the efficacy of regulatory controls on pollutant discharges and to assess the health status of ecosystems. Within this perspective, this study aimed to monitor the coastal trace element contamination of the whole Mediterranean, using Posidonia oceanica (L.) Delile as bioindicator. But sustainable coastal management also requires the development of appropriate classification systems intended, among other purposes, for environmental managers and policy makers. The combined utilization of several complementary monitoring tools - water quality scale, pollution index, spatial analysis - successfully led to the development of such an operational classification system: it allowed to assess contamination threats and to depict contamination gradients of the entire Mediterranean, while assessing more regional and local impacts. Consequently, such holistic approaches should be privileged to accurately monitor the contamination rate of coastal waters and to transfer relevant information on this composite problem to environmental managers and policy makers. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailDGTs, a complementary tool towards more efficient biomonitoring practices
Richir, Jonathan ULg; Lepoint, Gilles ULg; Donnay, Annick et al

Conference (2015, October 01)

Among the diversity of contaminants, trace elements (TEs) remain of concern because of their persistence, their ability to accumulate in biota and their toxicity. The direct measurement of their dissolved ... [more ▼]

Among the diversity of contaminants, trace elements (TEs) remain of concern because of their persistence, their ability to accumulate in biota and their toxicity. The direct measurement of their dissolved concentrations only gives punctual and fluctuating information, and often remains below detection limits of analytical methods. The more appropriate use of sentinel organisms, or bioindicators, to monitor TEs has thus often been preferred in environmental surveys. The introduction of the diffusive gradients in thin films (DGTs) technique has however participated to progressively change this binary view - bioindicator vs water - of the coastal monitoring of TEs, and DGTs rapidly became a relevant complementary tool to bioindicators, has illustrated below. In the framework of the STARECAPMED project, the ecology and the ecotoxicology of TEs were studied in the seagrass Posidonia oceanica (L.) Delile and the mussel Mytilus galloprovincialis Lamarck, 1819. DGTs (free- and pore-water probes) were deployed before sampling of organisms. TEs were also analyzed in suspended matter (dissolved and suspended-particulate TE speciation). Studies were performed in the Calvi Bay (Corsica, France), northwestern Mediterranean. TE concentrations in organisms and suspended matter or in DGT resins were measured by DRC-ICP-MS after HNO3/H202 mineralization or after a 24h elution in HNO3 1M, respectively. (1) TE bioaccumulation was first seasonally studied in P. oceanica over 3 years. Dissolved TE concentrations monitored with DGTs were low to very low. TE bioaccumulation dynamics in P. oceanica could thus be linked to the natural physiological cycle of the plant, in clean environmental conditions. (2) To complement that field survey, isolated seagrasses were in situ contaminated with TEs at environmental relevant concentrations. Through the use of DGTs, TE uptake kinetics were modelled for seagrasses exposed to know bioavailable concentrations of contaminants, as were loss kinetics during the following depuration phase. The TE sequestration ability of a healthy P. oceanica meadow facing sudden trace metal contamination events could also be quantified. (3) The deployment of pore-water DGT probes in bare-sand or seagrass colonized sediments further showed that, through its stabilizing function of the seabed, P. oceanica maintained higher TE levels in the pore-water. P. oceanica meadows thus offer a significant “depuration-filtering” ecological service along highly anthropized Mediterranean coasts. M. galloprovincialis are widely used in large spatial scale coastal monitoring surveys. (4) The deployment of caged mussels together with DGTs showed that the little contaminated water body of the Calvi Bay was relatively homogenous. It also allowed to calculate TE bioaccumulation towards mussels in reference conditions, and to compare it to native mussel populations. (5) Finally, during a 5 months mussel caging survey, mussels and suspended matter were collected weekly to monthly, such as were deployed DGTs. The physiological status of mussels, the speciation of TEs between their dissolved and suspended-particulate phases, and their relative influence on TE bioaccumulation dynamics in mussels were investigated. In conclusion, these case studies properly demonstrate how DGT probes can be used as a relevant and complementary tool to bioindicators. Their concomitant use should therefore be privileged in monitoring surveys. [less ▲]

Detailed reference viewed: 29 (2 ULg)
Full Text
Peer Reviewed
See detailTrace metal speciation? An essential aspect of biomonitoring to avoid wrong conclusions
Richir, Jonathan ULg; Lepoint, Gilles ULg; Donnay, Annick et al

Poster (2015, September 29)

The Mediterranean mussel Mytilus galloprovincialis is widely used as a bioindicator species in active monitoring surveys. As a filter feeder artificially maintained in the water column, it bioaccumulates ... [more ▼]

The Mediterranean mussel Mytilus galloprovincialis is widely used as a bioindicator species in active monitoring surveys. As a filter feeder artificially maintained in the water column, it bioaccumulates trace metals from the surrounding water in their dissolved and particulate forms. However, most monitoring surveys don’t take into account that speciation aspect when studying trace metal accumulation kinetics in mussels. In the framework of the STARECAPMED project, we monitored trace metal concentrations in the flesh of mussels together with their “most bioavailable” dissolved and particulate fractions in the water column for almost 5 months (February-June 2011). Mussels were purchased from 2 little contaminated French shellfish farms (SARL Etang de Diane and ferme marine des Aresquiers), placed in several pouches to allow regular sampling, and immerged near the Oceanographic Research Station STARESO in the Calvi bay, northwestern Corsica. Mussels and water samples for suspended matter filtration were collected every week to two weeks, as were deployed DGTs. Seawater samples were filtered through 47 mm hydrophilic PTFE membrane filters with a 0.45 µm pore size until clogging. In the laboratory, mussel flesh and filters were digested in Teflon vessels with acids (HNO3/H202) in a closed microwave digestion lab station. DGT resins were eluted for 24h in 1.0 M HNO3. Trace metal concentrations (Cr, Mn, Co, Ni, Cu, Zn, Ag, Cd, Pb) were measured by DRC-ICP-MS. Analytical accuracy was checked by analyzing CRMs. All the studied metals except Pb and Zn were present in the water column to over 80% in their dissolved form. The contribution of the dissolved pathway was thus likely to be predominant in the oligotrophic Calvi bay. Dissolved trace metals showed little temporal variability of their levels, likely resulting from the integration over time of their levels in the DGT probes and the lack of seasonality of this fraction. In contrast, Zn showed great variability of its particulate fraction during the survey. Such temporal variability was also observed for Cr, more abundant in its particulate form at the end of the survey, and for Mn and Pb that conversely tended to decrease. The dynamic of trace metals in the mussel flesh is regulated by the environmental bioavailability of dissolved and particulate metals, the ecophysiological status of mussels and the trophic conditions of the water body. In the oligotrophic Calvi bay, showing background contamination levels by metals, the trophic conditions played a major role once out of the spring plankton bloom. It led to the increase of metal concentrations measured in the flesh of mussels undergoing starvation. However, some metals such as Cu and Co displayed only little temporal variations of their concentrations, these essential micronutrients being well regulated. The combined study of trace metal bioavailability and mussel ecophysiology in defined environmental conditions allows discriminating against biotic and abiotic factors regulating contaminant uptake in mussels, thus avoiding wrong conclusions about the observed dynamics of the studied contaminants. Mussels are a good proxy of coastal water quality, but their proper use notably requires adjustment of raw contaminant concentrations with trophic status of monitored sites. [less ▲]

Detailed reference viewed: 28 (0 ULg)
Full Text
See detailSTARECAPMED (STAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts) - Année 2014. Rapport de recherches.
Richir, Jonathan ULg; Abadie, Arnaud ULg; Binard, Marc ULg et al

Report (2015)

La prise de conscience, par le grand public, de l'impact grandissant de l'homme sur l'océan est récente. Elle se traduit par une volonté politique sincère de correction par des mesures de protection, de ... [more ▼]

La prise de conscience, par le grand public, de l'impact grandissant de l'homme sur l'océan est récente. Elle se traduit par une volonté politique sincère de correction par des mesures de protection, de gestion et de développement durable. Ces politiques, et leurs conséquences économiques et sociétales lourdes, ne peuvent être acceptées que si les décisions se fondent sur des connaissances scientifiques incontestables et montrent des résultats scientifiquement prouvés. Par ailleurs, ces décisions doivent prendre en compte des impacts qui s'opèrent à des échelles de temps et d’espace très variables, de quelques heures à plusieurs dizaines d’années et de quelques mètres à plusieurs milliers de km. En termes politiques, l'information scientifique nécessaire à la prise de décision doit pouvoir couvrir les différentes échelles depuis le niveau local et régional, jusqu'à l'échelle nationale, européenne voire globale, et cela sur le plus long terme possible. Enfin, pour être complète, l'information scientifique sur les écosystèmes marins doit pouvoir répondre à trois questions objectives : (i) quel est l'état? (ii) quelle est l'évolution? (iii) quels sont les mécanismes et processus mis en jeux? et à une question plus prospective : (vi) que peux-t-on prévoir et comment agir? Le présent rapport ne peut pas, à lui seul, refléter toute la richesse du programme STARECAPMED. En 3 ans, STARECAPMED a généré plusieurs centaines de milliers de données nouvelles, ré-exploité plusieurs centaines de publications, rapports et autres enregistrements passés et présents. Le programme a aussi généré de nombreux documents, rapports et mémoires. Enfin, des publications internationales et des thèses de doctorat sont en cours de réalisation ou abouties. Afin de rester lisible, nous avons donc choisi de présenter ce rapport 2014 sous la forme de 12 exemples parmi les travaux en cours. Ces exemples sont traités selon un schéma identique en 4 points simples : (i) La présentation du cas d’étude dans le projet global ; (ii),Les approches innovatrices développées ; (iii),La présentation de résultats marquants ; (iv),Les délivrables de STARECAPMED pour les politiques publiques. [less ▲]

Detailed reference viewed: 63 (28 ULg)
Full Text
Peer Reviewed
See detailMetal bioavailability and bioaccumulation in the polychaete Nereis virens (Sars): the effects of site-specific sediment characteristics
Pini, Jennifer; Richir, Jonathan ULg; Watson, Gordon

in Marine Pollution Bulletin (2015), 95(2), 565575

The present study investigates the relationships between copper (Cu) and zinc (Zn) concentrations in sediment, pore water and their bioaccumulation in the polychaete Nereis (Alitta) virens, as well as the ... [more ▼]

The present study investigates the relationships between copper (Cu) and zinc (Zn) concentrations in sediment, pore water and their bioaccumulation in the polychaete Nereis (Alitta) virens, as well as the importance of site-specific sediment characteristics in that process. Sediment, pore water and N. virens were sampled from seven sites with different pollution histories along the English Channel coast. Results showed that site-specific metal levels and sediment characteristics were important in determining the bioavailability of metals to worms. Significant correlations were found between Cu in the sediment and in the pore water and between Zn in the pore water and in N. virens. Zn from the pore water was thus more readily available from a dissolved source to N. virens than Cu. Data also showed that metal concentrations in N. virens were lower than those found in other closely related polychaetes, indicating that it may regulate tissue concentrations of Cu and Zn. [less ▲]

Detailed reference viewed: 57 (5 ULg)
Full Text
Peer Reviewed
See detailSeagrasses or caged mussels to bioassess the contamination rate of Mediterranean coastal waters? That is the question
Richir, Jonathan ULg; Galgani, François; Benedicto, José et al

in PeerJ (2015, May)

Biological indicators have the capacity to integrate the temporal changes of contaminants, concentrations or fluxes over various time-scales, and are thus considered as interesting tools for water quality ... [more ▼]

Biological indicators have the capacity to integrate the temporal changes of contaminants, concentrations or fluxes over various time-scales, and are thus considered as interesting tools for water quality biomonitoring. Since the mid-70ies, French programs have developed water monitoring approaches based on the use of bivalve molluscs; and recently the natural background and the extent of water contamination were bioassessed at the scale of the whole western Mediterranean. But even if bivalve molluscs are viewed as reliable bioindicators, their use is not always made easy as a result of their absence in numerous coastal regions that force their transplantation (cages) during several months before their sampling and analysis. This weakness led several scientists to evaluate the bioindicator abilities of other marine organisms. Seagrasses, whose ability to bioaccumulate contaminants proportionally to environmental contamination levels has been clearly demonstrated, have thus been proposed as an appropriate alternative tool for coastal water quality assessment. Very little studies have however so far considered the combined utilization of these two groups of bioindicator organisms, i.e. caged bivalve molluscs and seagrasses. In the framework of the STARECAPMED project, we therefore compared and discussed the bioaccumulation of trace elements in the Neptune grass Posidonia oceanica and in caged Mediterranean mussels Mytilus galloprovincialis. The sampling was performed at the scale of the western Mediterranean. The two species told two contamination stories which, although sometimes different, showed to be complementary. P. oceanica and M. galloprovincialis bioaccumulated dissolved trace elements from the water column and thus provided information regarding trace element contamination severity integrated over several days to a few months. Seagrasses, strongly rooted in the sediments, reflected the long-term exposure to trace elements since sediments offer a degree of time integration over several years to decades. Caged mussels, as filter feeder artificially maintained in the water column, bioaccumulated trace elements from their particulate phase, and therefore gave valuable information regarding continental-terrigenous inputs to coastal waters. In conclusion, seagrasses and mussels should neither supplant, nor substitute, but rather complement each other in order to provide the full time- and space-integrated coastal contamination story of the Mediterranean. [less ▲]

Detailed reference viewed: 28 (10 ULg)
Full Text
Peer Reviewed
See detailTrace element contamination severity of coastal waters: A first bioassessment at the scale of the whole Mediterranean Sea
Richir, Jonathan ULg; Salivas-Decaux, Maylis; Lafabrie, Céline et al

in PeerJ (2015, May)

Human activities generate large volumes of waste that supply marine coastal environments in pathogens, organic matter, nutrients and toxicants. Among the wide range of toxicants are trace elements. Since ... [more ▼]

Human activities generate large volumes of waste that supply marine coastal environments in pathogens, organic matter, nutrients and toxicants. Among the wide range of toxicants are trace elements. Since the latter are toxic for aquatic organisms from threshold levels and as they are therefore likely to cause multiple damage to the population, the community and the ecosystem levels, their environmental occurrence has to be accurately monitored in order to guarantee appropriate environmental management of coastal zones and to preserve marine coastal ecosystems and the goods and services they provide. In the framework of the STARECAPMED project, the present study aimed to monitor, for the first time, the coastal contamination of the entire Mediterranean by As, Ag, Cd, Cu, Hg, Ni and Pb, using Posidonia oceanica (L.) Delile as bioindicator species. But sustainable coastal management also requires the development of appropriate contamination classification systems intended, among other purposes, for environmental managers and policy makers. The combined utilization of several complementary monitoring tools, i.e. water quality scale, pollution index (TEPI and TESVI) and spatial analysis (PCA, CA, correlation analysis and GIS mapping) successfully led to the development of an operational classification system of this kind. In particular, the mapping of the trace element contamination according to a new proposed 5-level water quality scale using the quantile method precisely outlined the contamination severity along Mediterranean coasts and facilitated interregional comparisons. The reliability of the use of P. oceanica as bioindicator species was further again demonstrated through several global, regional and local detailed case studies. In conclusion, holistic approaches such as developed in the present study should be privileged to accurately monitor the contamination rate of coastal waters and to transfer relevant information on this composite problem to environmental managers and policy makers. [less ▲]

Detailed reference viewed: 47 (10 ULg)
Full Text
Peer Reviewed
See detailBioassessment of trace element contamination of Mediterranean coastal waters using the seagrass Posidonia oceanica
Richir, Jonathan ULg; Salivas-Decaux, Maÿlis; Lafabrie, Céline et al

in Journal of Environmental Management (2015), 150

A large scale survey of the trace element (TE) contamination of Mediterranean coastal waters was performed from the analysis of Ag, As, Cd, Cu, Hg, Ni and Pb in the bioindicator Posidonia oceanica ... [more ▼]

A large scale survey of the trace element (TE) contamination of Mediterranean coastal waters was performed from the analysis of Ag, As, Cd, Cu, Hg, Ni and Pb in the bioindicator Posidonia oceanica, sampled at 110 sites differing by their levels of exposure to contaminants. The holistic approach developed in this study, based on the combined utilization of several complementary monitoring tools, i.e. water quality scale, pollution index and spatial analysis, accurately assessed the TE contamination rate of Mediterranean coastal waters. In particular, the mapping of the TE contamination according to a new proposed 5-level water quality scale precisely outlined the contamination severity along Mediterranean coasts and facilitated interregional comparisons. Finally, the reliability of the use of P. oceanica as bioindicator species was again demonstrated through several global, regional and local detailed case studies. NB: The designations employed and the presentation of the information in thisdocument do not imply the expression of any opinion whatsoever on the part of the authors concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. [less ▲]

Detailed reference viewed: 126 (32 ULg)
Full Text
Peer Reviewed
See detailA consensual Diving-PAM protocol to monitor Posidonia oceanica photosynthesis
Gobert, Sylvie ULg; Lepoint, Gilles ULg; Silva, João et al

in PeerJ (2015)

The seagrass Posidonia oceanica is widely recognized as an effective bioindicator of the health status of Mediterranean coastal waters. Chlorophyll fluorescence measurements, in particular through the ... [more ▼]

The seagrass Posidonia oceanica is widely recognized as an effective bioindicator of the health status of Mediterranean coastal waters. Chlorophyll fluorescence measurements, in particular through the Pulse Amplitude Modulated (PAM) fluorometry method, are performed to study aquatic plant ecology and vitality and to assess their responses to diverse stressful factors. However, the current understanding of P. oceanica photosynthetic responses to environmental stresses does only allow scientists to use the PAM-method as a complementary tool to other more-robust monitoring techniques. Consequently, a more in-depth knowledge of the natural causes of variability of P. oceanica photosynthetic responses are a prerequisite to any surveys relying on that time and cost-effective method. In the framework of the STARECAPMED project, this work aimed to determine the influence of several environmental (depth, daytime, season) and plant-specific characteristics (leaf age, leaf part analyzed, epiphytic coverage) on the photosynthetic responses (Y, ETR, RLC) of P. oceanica. Water temperature, irradiance and several biochemical parameters of the seagrass (chl.a, chl.b, C, N, P, micronutrients such as Fe, Cu) were measured as well. The field survey was performed in a pristine meadow in the Calvi Bay, Corsica. Environmental and plant-physiological characteristics deeply influenced P. oceanica photosynthetic responses. As an example, ETR decreased with depth, contrary to Y that mostly increased. ETR was lower in the basal part of leaf blade, and the epiphytic coverage of leaf tips slightly increased their ETR compared to leaf tips cleaned of epiphytes. Depth and leaf part-related variations in RLC were also observed. Because of this natural variability, it appears essential to develop a consensual protocol of chlorophyll fluorescence measurements to publish reliable and comparable results between studies. We therefore notably suggest to perform measurements close to midday, when photosynthetic responses are the highest; at 10-15 m depth in order to avoid, among others, low depth light irradiance variability; on the middle part of the 3rd-4th external leaf, well developed, highly photosynthetic, and little epiphyted. Finally, because P. oceanica fluorescence was correlated with N, P and chl.b leaf contents, the PAM-method could afterwards be used as bioindicator technique, according to the protocol proposed. [less ▲]

Detailed reference viewed: 42 (7 ULg)
Full Text
Peer Reviewed
See detailTrace element kinetics in caged Mytilus galloprovincialis
Richir, Jonathan ULg; Lepoint, Gilles ULg; Donnay, Annick et al

Poster (2014, December)

Trace elements (TEs) remain contaminants of concern because of their persistence, ability to concentrate in organisms and toxicity. The Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819 is a ... [more ▼]

Trace elements (TEs) remain contaminants of concern because of their persistence, ability to concentrate in organisms and toxicity. The Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819 is a relevant bioindicator of TE coastal contamination. However, little research has studied the combined influence of environmental condition changes and physiological processes on their kinetics in that species. Caged M. galloprovincialis were thus immerged in 2 contrasted pristine Corsican (France) coastal environments, the semi-enclosed Diane salty pond and the open Calvi Bay, from February to June 2011. Mussels were regularly sampled to study the kinetics of 19 TEs in their flesh; dissolved and particulate TEs were also monitored. The primary production and the water physico-chemical variables were measured, and meteorological data were purchased from Météo-France. TE kinetics in mussels differed between sites. Mussel spawning, a temperature and saline-induced physiological process that occurred about 10 days later in the Diane pond, was followed by a short time increase of TE levels in the mussel flesh. Mussel contamination also evolved according to changes of their respective environmental TE levels. Raining events temporary led, in the Diane pond, to the water enrichment with TEs, nutrients and detrital material, to peaks of primary production and to the increase of TE concentrations in the mussel flesh. This step by step evolution of TE levels in the environment and mussels was afterwards followed by a rapid return to initial conditions. In the open Calvi Bay, these fast and balanced kinetics were not so obvious, because of the rapid dilution of environmental constrain effects in the Bay. Mussels are often used as bioindicator in estuaries and coastal enclosed meadows with rapidly changing environmental conditions. In such conditions, the influence of the environment on TE kinetics in mussels must be considered, in addition to physiological processes, when monitoring the TE coastal contamination. [less ▲]

Detailed reference viewed: 67 (13 ULg)
Full Text
Peer Reviewed
See detailEcology of 20 trace elements in Mytilus galloprovincialis
Richir, Jonathan ULg; Lepoint, Gilles ULg; Lejeune, Pierre et al

Conference (2014, December)

Trace elements (TEs) are considered as non-degradable pollutants. This persistent character can alter their natural biogeochemical balance in contaminated environments. TEs are further toxic for aquatic ... [more ▼]

Trace elements (TEs) are considered as non-degradable pollutants. This persistent character can alter their natural biogeochemical balance in contaminated environments. TEs are further toxic for aquatic organisms from threshold levels and are thus likely to cause multiple damages to the population, the community and the ecosystem levels. For these reasons, their environmental occurrence has to be accurately monitored. The main interest of the use of quantitative sentinel organisms to this end, or bioindicator species, is their capacity to give information on the bioavailability of environmental contaminants. Mussels from the genus Mytilus are particularly well suited organisms for the monitoring of the coastal contamination. Native wild and cultured Mytilus galloprovincialis Lamarck, 1819 have been widely used since around 40 years to this purpose along coasts of the eastern Atlantic and the Mediterranean. But the accurate use of a bioindicator relies on the detailed knowledge of its ecophysiology and the influence of environmental variables on the bioaccumulation processes. In the framework of the STARECAPMED project, the ecology of 20 TEs in M. galloprovincialis is therefore investigated. The mussel morphometry and biology firstly define the TE accumulation processes. Accumulated TE are internally regulated and redistributed between body compartments; these internal processes notably depend on the essential or non-essential character of TEs. As filter feeder, mussels accumulate soluble and suspended TEs whose environmental levels are determined by the geomorphology, the physico-chemistry and the hydrology of monitored coastal meadows. All these factors are acting together to modulate the TE accumulation processes in mussels. TE bioaccumulated levels further balance quickly when any physiological or environmental changes occur in order to reach a new steady-state with environmental TE loads. The ecology of TEs in M. galloprovincialis is thus complex and very dynamic; these considerations must be taken into account when monitoring the chemical contamination of coastal meadows. [less ▲]

Detailed reference viewed: 63 (13 ULg)
Full Text
Peer Reviewed
See detailThe influence of bioavailable copper and zinc concentrations on metallothionein levels, DNA damage and gene expression in the polychaete Nereis (Alitta) virens (M. Sars, 1835)
Pini, Jennifer; Richir, Jonathan ULg; Watson, Gordon

Poster (2014, December)

Nereis (Alitta) virens is an ecologically and commercially important polychaete of intertidal soft sediment and an ideal species to investigate long term effects of metals. Using a spike approach, worms ... [more ▼]

Nereis (Alitta) virens is an ecologically and commercially important polychaete of intertidal soft sediment and an ideal species to investigate long term effects of metals. Using a spike approach, worms (1-3 g) were incubated for nine months in sediments spiked at environmentally relevant concentrations of copper, zinc and copper & zinc together: low (copper: 70 mg kg-1, zinc: 200 mg kg-1), medium (copper 120 mg kg-1, zinc: 270 mg kg-1) and high (copper 575 mg kg-1, zinc: 1160 mg kg-1) concentrations. These concentrations were based on an extensive sampling regime of sediment, pore water and worms from seven sites with different levels of contamination across the UK. Worms were fed and maintained under ambient conditions in a flow-through seawater system and sampled at 3, 6 and 9 months. Using BCR sequential extraction, bioavailable metal concentrations in the sediment were assessed in addition to pore water and tissues metal concentrations. The induction of metallothionein (MT) activity, especially at month 6, revealed the detoxification potential of N. virens under metal stress conditions. Significant correlations were obtained between copper bioavailable concentrations in the sediment and MT levels at month 3 and between zinc bioavailable concentrations in the sediment and MT levels at month 6. The highest DNA damage was recorded at month 3 for high copper & zinc combined treatment with 36.44%. Significant correlations were obtained between sediment bioavailable metal concentrations and DNA damage. In addition, the study of metal induced gene expression will reveal for the first time metal regulation process in the polychaete N. virens. This study showed that (1) not only high copper was toxic to N. virens but high copper & zinc combined treatment was the most toxic to the worms and (2) MT and DNA damage were sensitive and reliable endpoints used to evaluate copper and zinc toxicity. [less ▲]

Detailed reference viewed: 32 (0 ULg)
Full Text
Peer Reviewed
See detailAnalysing spatiotemporal changes in sediment contamination
Richir, Jonathan ULg; Pini, Jennifer; White, Shannon et al

Poster (2014, November)

Coastal environments are subjected to anthropogenic threats, of which pollution by trace elements (TEs). They remain chemicals of concern because of their toxicity, their ability to be concentrated in ... [more ▼]

Coastal environments are subjected to anthropogenic threats, of which pollution by trace elements (TEs). They remain chemicals of concern because of their toxicity, their ability to be concentrated in biota and their persistence in sediment. Aware of these threats, monitoring agencies perform large environmental surveys. However, the databases generated often remain underexploited, even though they represent an important source of information for scientists. As a case study, we focused on the highly industrialized and developed coastal area of the Solent, south coast of the UK, which is also a European Marine site with protected habitats and species. To date, no scientific-based spatiotemporal trend has been published regarding its pollution in TEs. But mining of existing databases requested from the Environmental Agency and the Marine Environment Monitoring and Assessment National database showed that sediment from 32 sites were/are indeed monitored for that purpose, covering a 22 years period (1992-2013). Temporal trend analysis showed that sediment contamination significantly decreased during that time interval (45 % decrease in median). However, all TEs still show concentrations above Sediment Quality Guidelines. Important spatial variability is also present, presumably linked to the distribution of pollutant anthropogenic sources. Taken together, these data have been used to provide stakeholders with relevant scientific based tools, i.e. GIS maps of the contamination in TEs in the Solent. This regional-level assessment enables local stakeholders to create bridges between environmental scientists and local authorities and valorizes the existing databases, for future governance at the regional and national scales. [less ▲]

Detailed reference viewed: 18 (0 ULg)
Full Text
Peer Reviewed
See detailThe conceptualization of trace element flows within Posidonia oceanica meadows: a collaborative proposal to fill knowledge gaps
Richir, Jonathan ULg; Gobert, Sylvie ULg

in Langar, H.; Bouafif, C.; Ouerghi, A. (Eds.) Proceedings of the 5th Mediterranean Symposium on Marine Vegetation (2014, October)

The Mediterranean seagrass Posidonia oceanica (L.) Delile is regarded as a relevant indicator of bioavailable trace elements (TEs) since it efficiently and proportionally bioaccumulates these chemicals ... [more ▼]

The Mediterranean seagrass Posidonia oceanica (L.) Delile is regarded as a relevant indicator of bioavailable trace elements (TEs) since it efficiently and proportionally bioaccumulates these chemicals from its surrounding environment. Recent studies have further brought supplementary insights in our understanding of the processes driving TE kinetics within that species. But at a higher degree of organization, the distribution and flows of TEs between P. oceanica meadow components, i.e. seagrass shoots, epiphytes, associated algae and animals and detritus, have not been investigated yet. The present study therefore aims to propose a conceptualization model of P. oceanica meadows, regarded as the juxtaposition of the 5 separate components listed above exchanging flows of TEs between themselves and with their environment, i.e. water and sediment. This model can be drawn in energy circuit language. By writing such a model, one in essence is writing equations describing a system. To be relevant, its elaboration requires the compilation of a large amount of quantitative data. This conceptualization can thus be regarded as a collaborative innovation requiring scientists to fill the model through the continuous supplement of new data. In fine, this model will lead to the exact quantification of the role played by P. oceanica meadows in the coastal biogeochemistry of TEsin the Mediterranean. [less ▲]

Detailed reference viewed: 46 (8 ULg)
Full Text
Peer Reviewed
See detailTrace element bioaccumulation and compartmentalization in the invasive algae Caulerpa racemosa var. cylindracea from the Calvi Bay, Corsica
Gobert, Sylvie ULg; Richir, Jonathan ULg

in Langar, H.; Bouafif, C.; Ouerghi, A. (Eds.) Proceedings of the 5th Mediterranean Symposium on Marine Vegetation (2014, October)

The algae Caulerpa racemosa var. cylindracea (Sonder) was first observed along Corsican coasts in 2002 (Ruitton et al., 2005), and more recently in the Calvi Bay (northwestern Corsica) in 2008. Numerous ... [more ▼]

The algae Caulerpa racemosa var. cylindracea (Sonder) was first observed along Corsican coasts in 2002 (Ruitton et al., 2005), and more recently in the Calvi Bay (northwestern Corsica) in 2008. Numerous works have studied the distribution of that invasive species and the factors driving its rapid expansion, as well as the resulting ecological impacts on native coastal communities (Klein and Verlaque, 2008). However, very little is known regarding C. racemosa biochemistry and its natural ability to concentrate trace elements (TEs). In the framework of the STARECAPMED project, this work therefore aimed to study the bioaccumulation and the compartmentalization of 19 TEs in this macroalgae. [less ▲]

Detailed reference viewed: 28 (7 ULg)
Full Text
See detailSpatiotemporal evolution of the distribution of trace elements in the sediments of the English Channel
Richir, Jonathan ULg; Pini, Jennifer; White, Shannon et al

Scientific conference (2014, September 18)

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailMapping key pollutants in the English Channel region: the Channel Catchments Cluster (3C) cross-border project
Richir, Jonathan ULg; Pini, Jennifer; Watson, Gordon

Conference (2014, August 16)

The EU Water Framework Directive was a response to concerns about the previous disparate ways in which water quality was managed under Member State law and early European Directives. Within this context ... [more ▼]

The EU Water Framework Directive was a response to concerns about the previous disparate ways in which water quality was managed under Member State law and early European Directives. Within this context, the Interreg IVA France (Channel) England Region established the ‘sustainable environmental development of this common space’ as one of its priorities to integrate areas that face common problems. The wide variety of cooperative cross-border projects have brought together UK and French scientists and environmental managers to develop practical environmental management tools for the region (3Cs cluster). Using the Solent in the UK as a case study, maps of key pollutants (e.g. metals such as Zn and Cu) will be produced to assess their spatial diversity within the sediment. The incorporation of historical datasets will also provide a temporal component. The inclusion of bioavailable fractions (using sequential extraction methods) will enable the pollutants to be linked to the tissue concentrations of key benthic species such as the polychaete Nereis virens and possible impacts. Not only will this information provide a detailed account of the water quality of key areas of the English Channel, but it will also highlight the gaps in the data and sampling regimes that are necessary to achieve good environmental status for the future, thus ensuring more effective European environmental policy regarding the long-term protection and conservation of aquatic ecosystems. [less ▲]

Detailed reference viewed: 41 (1 ULg)