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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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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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)

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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 ▲]

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See detailSite-specific sediment characteristics impact on metal bioavailability and bioaccumulation in the Polychaete Nereis virens
Pini, Jennifer; Richir, Jonathan ULg; Watson, Gordon

Poster (2014, May 15)

The king ragworm (Nereis virens) is a cosmopolitan species of soft sediment inter-tidal communities and is known to be impacted by various pollutants. More precisely, in many coastal locations, N. virens ... [more ▼]

The king ragworm (Nereis virens) is a cosmopolitan species of soft sediment inter-tidal communities and is known to be impacted by various pollutants. More precisely, in many coastal locations, N. virens is exposed to a range of metals including copper and zinc which are known to be highly toxic. However, the relationships between metal bioavailable concentrations in the sediment, the pore water and the tissues of N. virens have not yet been investigated in this is ecologically and commercially important species. Hence, to investigate these relationships, sediment, pore water and associated worms samples were collected from seven sites along the English Channel coast of the UK, chosen for their different pollution histories. The BCR three-step sequential extraction procedure was used to assess the bioavailable metal concentrations in the sediment, in conjunction to standard extraction techniques to determine the tissue and the pore water concentrations. All samples were measured by Atomic Absorption Spectroscopy (FAAS). Results from correlation analyses showed that site specificities and metal pollution histories along with sediment characteristics (organic content and particle size) were important factors regarding the bioavailability of copper and zinc to worms. Indeed, sediment organic content and grain size were positively correlated to metal bioavailable concentrations in the sediment. Strong correlations were found between copper bioavailability in the sediment and in the pore water and between zinc concentrations in the pore water and in N. virens. These results showed that zinc from the pore water was more readily bioavailable to N. virens than copper. However, our data suggested that N. virens accumulated metals regardless of the pollution history/level of the sites. In addition, our data showed that metal concentrations in N. virens were lower than those found in other closely related polychaetes such as N. diversicolor. This suggests that N. virens, unlike other polychaetes, is well adapted to highly contaminated sites by the possible use of specific metal regulation mechanisms, which would require further analysis. [less ▲]

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See detailCadmium and mercury sediment pollution along the British coastline of the Channel: A first spatio-temporal integrated approach
Richir, Jonathan ULg; Pini, Jennifer; Watson, Gordon

Poster (2014, May 15)

Cadmium (Cd) and Mercury (Hg) are 2 widespread trace metals occurring in both terrestrial and marine environments. They play no physiological role and are often toxic even at low concentrations and were ... [more ▼]

Cadmium (Cd) and Mercury (Hg) are 2 widespread trace metals occurring in both terrestrial and marine environments. They play no physiological role and are often toxic even at low concentrations and were therefore identified as priority hazardous substances under the European Water Framework Directive and included in the European List I of Dangerous Substances. Marine sediments are considered as the ultimate sink of non-degradable metals, where they can accumulate in considerable quantities. The UK coastline has been polluted with metals for decades or even centuries and, although many studies have monitored sediment metal loads in specific locations, there has been no recent systematic monitoring approach along the whole of the south coast. In addition, few reliable data exist on decadal temporal trends for most sediment pollutants. Focusing on Cd and Hg, we have investigated their spatial and temporal distribution in sediment samples collected from 42 sites along the English coast of the Channel from 1990 to 2010. From a temporal point of view, data analyses showed that mean Cd levels in sediments significantly decreased by 59 % during that period of time, from 0.78 to 0.32 mg kgDW-1 of sediments. This reflects a decrease globally to below the 0.70 mg kgDW-1 Cd Threshold Effect Level (TEL). Adverse effects caused by Cd on the biota should, therefore, be rare. Spatially, Cd displayed an east-to-west increase of its levels, with several western sites with Cd still above the TEL. Regarding Hg, sediment levels did not significantly change from 1990 to 2010, remaining approximately twice as high as the corresponding 0.13 mg kgDW-1 Hg TEL. Hg also displayed an east-to-west increase of its levels, whilst 55 % of monitored sites had a mean sediment Hg concentration in average 3.5 times higher than the TEL. Despite regulations, non-degradable metals such as Cd and Hg that have accumulated in sediments over considerable periods of time may consequently still pose threats to aquatic organisms, highlighting the need for continued extensive spatially and temporally integrated monitoring approaches. [less ▲]

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See detailTrace element bioaccumulation in rope-grown Mytilus galloprovincialis: knowledge update
Richir, Jonathan ULg; Gobert, Sylvie ULg

Poster (2014, May 12)

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the ... [more ▼]

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the use of bioindicator species, such as the Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819). That species has been widely used to monitor the chemical pollution of coastal ecosystems by Cr, Ni, Cu, Zn, Cd, Pb, As, Ag and V. Conversely, environmental levels of Be, Al, Fe, Mn, Co, Se, Mo, Sn, Sb and Bi have been little or not monitored so far in mussel watch programs. Bioaccumulation processes of these 19 TEs in rope-grown M. galloprovincialis purchased from a salt pond with good chemical water quality were thus investigated in the present study. Mussels efficiently accumulated the 19 studied TEs. Bioaccumulation processes were driven by numerous mutually dependent biological parameters such as the mussel size and flesh weight, the sex and the reproductive status and the body compartment considered. TE bioaccumulation was a power function of the mussel soft body dry weight; total contents linearly increased with the shell length. Small-size mussels overall concentrated more TEs, with a high interindividual variability, consequently influencing the modelling of their bioaccumulation in the whole rope population. Although a large range of rope-grown M. galloprovincialis sizes can be used for monitoring purposes, one will thus take care not to use extreme size individuals. The influence of gametogenesis in determining female body higher TE concentrations prior to spawning could not be neglected and varied depending on the element. TEs were preferentially accumulated in the hepatopancreas, except for Zn, Se, Cd and Mo, more concentrated in gills. Gametogenesis did not influence TE distribution between body compartments, but likely diluted their concentrations as a direct consequence of massive reproductive tissue production. So, results from the present study underlined the potential use of M. galloprovincialis in the biomonitoring of numerous little studied TEs and gave some insights into the decisive role played by some relevant biological parameters in bioaccumulation processes of the 19 investigated TEs in rope-grown mussels. [less ▲]

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See detailNew insights for an old topic: seagrasses as bioindicators of coastal trace element pollution
Richir, Jonathan ULg; Lejeune, Pierre; Gobert, Sylvie ULg

in ARGYRO ZENETOS, ZENETOS (Ed.) Mediterranean Marine Science (2014, March)

The marine magnoliophyte Posidonia oceanica (L.) Delile has been widely used since the mid-70th to biomonitor the coastal pollution of the Mediterranean in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe. In contrast ... [more ▼]

The marine magnoliophyte Posidonia oceanica (L.) Delile has been widely used since the mid-70th to biomonitor the coastal pollution of the Mediterranean in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe. In contrast, other trace elements (TEs) like As, V, Ag, Be, Al, Mn, Co, Se, Mo, Sn, Sb and Bi, many of them categorized as TEs of environmental emerging concern, have been subject to nearly no ecotoxicological survey with that species. It has been shown that the French Mediterranean littoral was submitted to local, diffuse and/or chronic contaminations both by TEs broadly or little biomonitored with P. oceanica; high TE levels could further be linked to specific anthropic activities such as agriculture (Mo), mining (Cr, Sb, Zn), industries (As), storage and refinement of oil products (V, Pb) or presence of major ports and urban centres (Sn, Bi, Ag). It seems therefore necessary to expand the short list of the seven metals commonly monitored to other TEs, what is today easily achievable as current analytical methods allow the simultaneous determination of all a series of TEs within the same sample. Furthermore, only a multielement analysis in appropriate bioindicator species allow to correctly intercompare the pollution status of numerous sampling sites. To do this, we have calculated proper environmental indices, the trace element pollution index TEPI and the trace element spatial variation index TESVI. The TEPI is an index of the global contamination of a site, giving the same weight to each TE after mean normalization of their environmental concentrations. The TESVI estimates the global spatial variability of environmental concentrations of each TE levels, taking into account both punctual contaminations in impacted sites and the overall coastal spatial heterogeneity between all monitored sites.These two indices were successfully applied both at large (French Mediterranean littoral) and small (a Bay) spatial scales. Furthermore, they can be used in the framework of an intercomparative study compiling data from any previous monitoring surveys. We also highlighted that the ecophysiology and surrounding levels of TEs influenced in an equivalent manner the bioaccumulation process of TEs in P. oceanica. Consequently, this natural cyclic evolution of TE concentrations should be systematically quantified in regional reference sites. Finally, the rapid and proportionnal accumulation of TEs in P. oceanica traps huge amounts of contaminants and can stock them for longer periods of time in their bellow grounds tissues. P. oceanica meadows therefore play an efficient role of natural filter of TE coastal pollutions. [less ▲]

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See detailA reassessment of the use of Posidonia oceanica and Mytilus galloprovincialis to biomonitor the coastal pollution of trace elements: New tools and tips
Richir, Jonathan ULg; Gobert, Sylvie ULg

in Marine Pollution Bulletin (2014), 89

The present study gives a summary using state-of-the-art technology to monitor Posidonia oceanica and Mytilus galloprovincialis as bioindicators of the pollution of the Mediterranean littoral with trace ... [more ▼]

The present study gives a summary using state-of-the-art technology to monitor Posidonia oceanica and Mytilus galloprovincialis as bioindicators of the pollution of the Mediterranean littoral with trace elements (TEs), and discusses their complementarity and specificities in terms of TE bioaccumulation. Furthermore, this study presents two complementary indices, the Trace Element Spatial Variation Index (TESVI) and the Trace Element Pollution Index (TEPI): these indices were shown to be relevant monitoring tools since they led to the ordering of TEs according to the overall spatial variability of their environmental levels (TESVI) and to the relevant comparison of the global TE pollution between monitored sites (TEPI). In addition, this study also discusses some underestimated aspects of P. oceanica and M. galloprovincialis bioaccumulation behaviour, with regard to their life style and ecophysiology. It finally points out the necessity of developing consensual protocols between monitoring surveys in order to publish reliable and comparable results. [less ▲]

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See detailThe effect of size, weight, body compartment, sex and reproductive status on the bioaccumulation of 19 trace elements in rope-grown Mytilus galloprovincialis
Richir, Jonathan ULg; Gobert, Sylvie ULg

in Ecological Indicators (2014), 36

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the ... [more ▼]

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the use of bioindicator species, such as the Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819). That species has been widely used to monitor the chemical pollution of coastal ecosystems by Cr, Ni, Cu, Zn, Cd, Pb, As, Ag and V. Conversely, environmental levels of Be, Al, Fe, Mn, Co, Se, Mo, Sn, Sb and Bi have been little or not monitored so far in mussel watch programs. Bioaccumulation processes of these 19 TEs in rope-grown M. galloprovincialis purchased from a salt pond with good chemical water quality were thus investigated in the present study. Mussels efficiently accumulated the 19 studied TEs. Bioaccumulation processes were driven by numerous mutually dependent biological parameters such as the mussel size and flesh weight, the sex and the reproductive status and the body compartment considered. TE bioaccumulation was a power function of the mussel soft body dry weight; total contents linearly increased with the shell length. Small-size mussels overall concentrated more TEs, with a high inter-individual variability, consequently influencing the modelling of their bioaccumulation in the whole rope population. Although a large range of rope-grown M. galloprovincialis sizes can be used for monitoring purposes, one will thus take care not to use extreme size individuals. The influence of gametogenesis in determining female body higher TE concentrations prior to spawning could not be neglected and varied depending on the element. TEs were preferentially accumulated in the hepatopancreas, except for Zn, Se, Cd and Mo, more concentrated in gills. Gametogenesis did not influence TE distribution between body compartments, but likely diluted their concentrations as a direct consequence of massive reproductive tissue production. So, results from the present study underline the potential use of M. galloprovincialis in the biomonitoring of numerous little studied TEs and give some insights into the decisive role played by some relevant biological parameters in bioaccumulation processes of the 19 investigated TEs in rope-grown mussels. [less ▲]

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See detailThe underestimation of seagrass biological cycle in the biomonitoring of coastal trace element pollution
Richir, Jonathan ULg; Sartoretto, Stéphane; Gobert, Sylvie ULg

Poster (2013, December)

Previous monitoring surveys using the Mediterranean seagrass Posidonia oceanica (L.) Delile mostly studied coastal pollutions in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe and the distribution of their ... [more ▼]

Previous monitoring surveys using the Mediterranean seagrass Posidonia oceanica (L.) Delile mostly studied coastal pollutions in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe and the distribution of their bioaccumulated levels between the seagrass compartments. In contrast, other trace elements (TEs) like As, V, Ag, Be, Al, Mn, Co, Se, Mo, Sn, Sb and Bi, many of them categorized as TEs of environmental emerging concern, have been subject to nearly no ecotoxicological survey with that species. Moreover, the understanding of the seasonal variation of TE levels according to the seagrass biological cycle, a prerequisite to the intercomparison of sites sampled at different periods of the year, has been little investigated. P. oceanica were thus seasonally collected for TE analyses from March 2008 to November 2010 in the Calvi Bay (Corsica, France), a reference site for the northwestern Mediterranean, and near the sewer outfall of Marseille city (France). Results showed that levels of the 19 studied TEs evolved seasonally according to the seagrass biological cycle. So, foliar levels of Cr, Pb, Mn or Bi, preferentially accumulated in older leaves, increased from spring to autumn, as the number of adult leaves. V, Se, As or Sb evolved similarly to the shoot foliar surface, reflecting the plant growth. Cu levels, an essential micronutrient, were lower when summer requirements for leaf growth were high. Al foliar levels evolved similarly to rhizome and root levels, resulting from its acropetal translocation. However, in the anthropized Marseille site, environmental variables non-intrinsic to the seagrass ecophysiology could perturb this seasonal variation. This survey allowed highlighting the proportionally equivalent roles played by both the seagrass biological cycle and its environment in the bioaccumulation process of TEs. This cyclic evolution should therefore be systematically quantified in regional reference sites in order to properly intercompare results from biomonitoring surveys. [less ▲]

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See detailRecent advances in the biomonitoring of trace elements using P. oceanica (L.) Delile
Gobert, Sylvie ULg; Richir, Jonathan ULg

in de Lange, Gert J.; Gacic, Miroslav; Romaña, Axel (Eds.) et al 40th CIESM Congress Proceedings (2013, November)

One of the most studied bioindicator in the Mediterranean is the seagrass Posidonia oceanica. Trace element (TE) monitoring surveys using that species have however mostly focussed on a few elements (e.g ... [more ▼]

One of the most studied bioindicator in the Mediterranean is the seagrass Posidonia oceanica. Trace element (TE) monitoring surveys using that species have however mostly focussed on a few elements (e.g. Pb, Cd), while numerous others, efficiently bioconcentrated by the plant and potentially toxic, have been barely or not studied (e.g. Ag, V, Bi). Furthermore, although P. oceanica bioaccumulation behaviour relies on synergistic effects between the sampling environment and its ecophysiology, this aspect has been mostly underestimated until now. This study presents recent advances in the biomonitoring of TEs using P. oceanica and insists on the necessity of developing consensual monitoring protocols in order to improve its use as bioindicator. [less ▲]

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See detailL’indice paysager Caulerpa racemosa “I.Ca.r”
Cariou, Nicolas; Chery, Aurélia; Jousseaume, Matthieu et al

in Ifremer (Ed.) CARtographie des HAbitats Marins Benthiques : de l'Acquisition à la Restitution (2013, March 27)

Depuis 2002, l’algue invasive Caulerpa racemosa var. cylindracea a été signalée au niveau de la Corse. Elle apparaît pour la première fois, en 2008, au niveau de la baie de Calvi (Corse). Depuis cette ... [more ▼]

Depuis 2002, l’algue invasive Caulerpa racemosa var. cylindracea a été signalée au niveau de la Corse. Elle apparaît pour la première fois, en 2008, au niveau de la baie de Calvi (Corse). Depuis cette époque, le nombre et la surface des sites envahis augmentent. L'analyse fine de l'évolution spatio-temporelle de sa distribution dans la zone prospectée confirme que C. racemosa colonise d'abord les sites profonds. A partir des différents stades de colonisation, un indice paysager (Indice Caulerpa racemosa: "I.Ca.r") adapté à la plongée en scaphandre autonome a été élaboré. "I.Ca.r" qui tient compte de l'expérience du plongeur, du type de substrat et de la superficie colonisée est un code à 8 caractères. Il permet une comparaison spatiale de sites colonisés et également une analyse de l'évolution temporelle de la colonisation. Mis au point en Baie de Calvi, l'indice paysager "I.Ca.r" peut être appliqué sur la Corse et sur l'ensemble de La Méditerranée. La méthodologie simple, résumée sur une fiche pourrait être distribuée dans les clubs de plongée et les informations envoyées au réseau Caulerpe par exemple. [less ▲]

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See detailExperimental in situ exposure of the seagrass Posidonia oceanica (L.) Delile to 15 trace elements
Richir, Jonathan ULg; Luy, Nicolas; Lepoint, Gilles ULg et al

in Aquatic Toxicology (2013), 140-141

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been used for trace element (TE) biomonitoring since decades ago. However, present informations for this bioindicator are limited mainly to ... [more ▼]

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been used for trace element (TE) biomonitoring since decades ago. However, present informations for this bioindicator are limited mainly to plant TE levels, while virtually nothing is known about their fluxes through P. oceanica meadows. We therefore contaminated seagrass bed portions in situ at two experimental TE levels with a mix of 15 TEs (Al, V,Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Ag, Cd, Pb and Bi) to study their uptake and loss kinetics in P. oceanica. Shoots immediately accumulated pollutants from the beginning of exposures. Once contaminations ended, TE concentrations came back to their original levels within two weeks, or at least showed a clear decrease. P. oceanica leaves exhibited different uptake kinetics depending on elements and leaf age: the younger growing leaves forming new tissues incorporated TEs more rapidly than the older senescent leaves. Leaf epiphytes also exhibited a net uptake of most TEs, partly similar to that of P. oceanica shoots. The principal route of TE uptake was through the water column, as no contamination of superficial sediments was observed. However, rhizomes indirectly accumulated many TEs during the overall experiments through leaf to rhizome translocation processes. This study thus experimentally confirmed that P.oceanica shoots are undoubtedly an excellent short-term bioindicator and that long-term accumulations could be recorded in P. oceanica rhizomes. [less ▲]

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See detailEstablishing research strategies, methodologies and technologies to link genomics and proteomics to seagrass productivity, community metabolism, and ecosystem carbon fluxes
Mazzuca, Silvia; Bjork, M; Beer, S et al

in Frontiers in Plant Science (2013), 4(38), 1-19

A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research.This enables the prediction of change and possibly the ... [more ▼]

A complete understanding of the mechanistic basis of marine ecosystem functioning is only possible through integrative and interdisciplinary research.This enables the prediction of change and possibly the mitigation of the consequences of anthropogenic impacts. One major aim of the European Cooperation in Science and Technology (COST) Action ES0609 “Seagrasses productivity. From genes to ecosystem management,” is the calibration and synthesis of various methods and the development of innovative techniques and protocols for studying seagrass ecosystems. During 10 days, 20 researchers representing a range of disciplines (molecular biology, physiology, botany, ecology, oceanography, and underwa- ter acoustics) gathered at The Station de Recherches Sous-marines et Océanographiques (STARESO, Corsica) to study together the nearby Posidonia oceanica meadow. STARESO is located in an oligotrophic area classified as “pristine site” where environmental distur- bances caused by anthropogenic pressure are exceptionally low. The healthy P. oceanica meadow, which grows in front of the research station, colonizes the sea bottom from the surface to 37 m depth. During the study, genomic and proteomic approaches were integrated with ecophysiological and physical approaches with the aim of understanding changes in seagrass productivity and metabolism at different depths and along daily cycles. In this paper we report details on the approaches utilized and we forecast the potential of the data that will come from this synergistic approach not only for P. oceanica but for seagrasses in general. [less ▲]

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See detailCoastal pollution of the Mediterranean and extension of its biomonitoring to trace elements of emerging concern
Richir, Jonathan ULg

Doctoral thesis (2012)

The Mediterranean Sea, a semi-enclosed sea with densely populated coasts, is submitted to numerous anthropogenic pressures: among them, the chemical pollution by traces elements. These pollutants, coming ... [more ▼]

The Mediterranean Sea, a semi-enclosed sea with densely populated coasts, is submitted to numerous anthropogenic pressures: among them, the chemical pollution by traces elements. These pollutants, coming from our continental activities, are transported through rivers or by air and accumulate in seas and oceans where they mainly affect coastal areas. During the 70ies, scientists suggested to use organisms, in particular mussels of the genus Mytilus, in order to evaluate the status of chemical contamination of coastal ecosystems. Biomonitoring was born. Since, many monitoring studies were published using various animal and vegetal species. Two of the most studied bioindicators species in the Mediterranean are the marine magnoliophyte Posidonia oceanica and the Mediterranean mussel Mytilus galloprovincialis. Monitoring studies with these two species have mainly focussed on contaminations by Cr, Ni, Cu, Zn, Cd, Pb (Mytilus galloprovincialis and Posidonia oceanica), Fe (Posidonia oceanica), As, V and Ag (Mytilus galloprovincialis). However, other trace elements like Be, Al, Mn, Co, Se, Mo, Sn, Sb and Bi have been subject to nearly no ecotoxicological survey. Furthermore the worldwide evolution of our technologies and of our lifestyle increases the extraction and production of trace elements (notably to answer needs of developing countries). The biomonitoring of the pollution by trace elements is henceforth a topical subject. The overall objective of this work was therefore to evaluate the potential use of Mytilus galloprovincialis and Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by Be, Al, Mn, Co, Se, Mo, Sn, Sb, Bi, Fe, As, V, and Ag. These trace elements, mostly little studied, can be categorized as elements of “environmental emerging concern”. A time-integrated efficient monitoring of trace elements requires the continuous survey of their environmental levels; we therefore also measured levels of trace elements classically monitored with these two species. Mytilus galloprovincialis and Posidonia oceanica complement each other in monitoring surveys. Both species accumulate pollutants dissolved in the water column. Posidonia oceanica, rooted in the seafloor, accumulates moreover pollutants stored in sediments in the long term. Mytilus galloprovincialis, as a filter feeder, further accumulate particulate pollutants suspended in the water column. The combined use of both bioindicators therefore provides a global view of the health status of the coastal environment (water, sediments, suspended matter). Our first goal was to measure, at the scale of the French Mediterranean littoral, the spatial variability of trace element contents in Posidonia oceanica, and to determine if trace elements of environmental emerging concern threaten the chemical integrity of coastal ecosystems. We observed that the large majority of trace elements little or no monitored with Posidonia oceanica showed an equivalent to higher spatial variability than elements classically monitored with that species. We also showed that the spatial variability could be associated to specific anthropic activities like agriculture (Mo), mining (Sb), storage and refinement of oil products (V), or the presence of harbours and major urban centres (Sn, Bi). Their monitoring, along with the one of trace elements classically studied in the Mediterranean, turns out to be essential. In addition, the in-depth study of the contamination state of the Calvi Bay (Northwestern coast of Corsica, France), enabled us to define (or re-define) this site as a reference site for the monitoring of the chemical pollution by trace elements in the Northwestern Mediterranean. We further studied the physiological mechanisms of accumulation, storage and excretion of trace elements by Posidonia oceanica. In situ contamination of seagrass bed portions allowed us to model the rapid kinetics of accumulation of contaminants by Posidonia oceanica shoots. Compartments of the plant answered differently to pollutant exposures. So, adult and senescent leaves assimilated pollutants less rapidly than young actively growing leaves. Trace elements, once accumulated, could be redistributed between the plant compartments, notably towards the rhizomes-roots systems buried in sediments. Our results experimentally showed that these below-ground organs could therefore play the role of biological archives for many elements. At the end of periods of exposure to pollutants, kinetics of decontaminations of Posidonia oceanica shoots were relatively fast and depended notably on the duration of the exposure to trace elements, on their toxic or essential character and on the studied compartment. We concluded that Posidonia oceanica was a sensitive bioindicator for the monitoring of the past and present coastal pollution by trace elements. We showed that Mytilus galloprovincialis efficiently accumulated trace elements of environmental emerging concern as well as elements classically studied with this bioindicator species. The physiology of mussels further conditioned their answers to pollutant exposures. Their reproductive cycle dissolved trace element concentrations during the massive production of gametes and conducted to differences more or less important between individuals of both sexes. The conservative character of the distribution of trace elements between the different body compartments of Mytilus galloprovincialis suggested an important physiological regulation of their internal levels. Finally, the size of mussels used in this study, harvested from an aquaculture farm, did not noticeably influence inter-individual concentrations, all mussels of a same rope having approximately the same age. In conclusion, this study enabled to improve and enlarge our state of knowledge about the monitoring of the pollution of the Mediterranean coastal environment by trace elements. In particular, both Mytilus galloprovincialis and Posidonia oceanica showed to be good candidates for the monitoring of trace elements of environmental emerging concern. [less ▲]

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