References of "Vermeulen, Simon"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailMultiscale variability of amphipod assemblages in Posidonia oceanica meadows
Sturaro, Nicolas ULg; Lepoint, Gilles ULg; Vermeulen, Simon et al

in Journal of Sea Research (in press)

The study of spatial patterns is of ecological importance in order to understand the causes of the distribution and abundance of organisms, and it also provides valuable basis for management and ... [more ▼]

The study of spatial patterns is of ecological importance in order to understand the causes of the distribution and abundance of organisms, and it also provides valuable basis for management and conservation. Amphipod crustaceans are key organisms in seagrass ecosystems. However, little attention has been paid to the spatial scales at which amphipod assemblages may vary. We examined variability patterns of amphipod populations inhabiting Posidonia oceanica meadows, over spatial scales spanning four orders of magnitude (1 to 1000 metres) and for two consecutive years. This study reports the scales that contributed most to spatial variation of amphipod assemblages and explores the potential processes of the observed patterns, with particular emphasis on habitat features. The number of species, the diversity and the density of some species, exhibited high variation across years. Most species showed the highest spatial variation in density and biomass at small scales (~1 and 10 m). Based on density data, the structure of amphipod assemblages did not differ at any scales investigated. The patchiness that occurred at small scales may have been only weakly related to habitat features. Instead, we postulated that behavioural processes of amphipods were likely good explanatory factors. Although, the small scale spatial variability can be an important feature of amphipod assemblages in P. oceanica meadows, many patterns probably remained undetected as they may occur at scales smaller than those investigated. [less ▲]

Detailed reference viewed: 22 (10 ULg)
Full Text
Peer Reviewed
See detailAssessment of Mytilus galloprovincialis to monitor 19 trace elements in the Calvi Bay
Richir, Jonathan ULg; Vermeulen, Simon; Biondo, Renzo ULg et al

Poster (2011, December 08)

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from ... [more ▼]

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from 10 to 100km. However, its relevance as bioindicator at smaller scales (100 m - 1 km) is poorly known. Moreover, the levels of some little studied trace elements (Al, V, Mn, Sb, Sn, Ag, Mo, Se, As, Co, Be, Bi), recently identified as potential pollutants of coastal environments, have not yet been assessed in that species. In this work, M. galloprovincialis was used to monitor the 19 listed trace elements at the scale of the Calvi Bay (NW Corsica, France). Additionally, we investigated decontamination kinetics and trace element tissue speciation before and after spawning. Mytilus galloprovincialis trace element levels reflect the good water quality of the Calvi Bay, showing little spatial variations either at 100m or 1km scales. Filter feeders are only influenced by their relatively homogeneous pelagic environment (dissolved trace elements and suspended particulate matters), in contrast to organisms which inhabit typically heterogeneous benthic habitats. This bioindicator, a convincing candidate for the monitoring of the 12 little studied trace elements, effectively accumulates the 19 studied elements to 105 seawater concentrations. Mytilus galloprovincialis rapidly equilibrates (within days) with its environment, and is therefore a good indicator of chronic and stable chemical pollutions. Tissue speciation shows that the most relevant organ to monitor trace elements is the hepatopancreas. However, the important variability induced by the reproductive cycle of mussels requires using this bioindicator during its sexual dormancy. [less ▲]

Detailed reference viewed: 47 (8 ULg)
Full Text
Peer Reviewed
See detailSeagrass response to in situ trace element contaminations
Richir, Jonathan ULg; Luy, Nicolas; Lepoint, Gilles ULg et al

Poster (2011, September)

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been widely used since the mid-seventies as bioindicator to monitor trace element (TE) coastal pollution. However, there is a lack of ... [more ▼]

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been widely used since the mid-seventies as bioindicator to monitor trace element (TE) coastal pollution. However, there is a lack of knowledge regarding to that seagrass contamination and decontamination kinetics. For the first time, Posidonia were experimentally in situ contaminated in 2009, at 10m depth in Calvi Bay (Corsica), by a mix of 15 TE (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Ag, Cd, Pb and Bi). Trace element concentrations were measured by DRC-ICP-MS in leaves, rhizomes and in overall shoots sampled at regular time intervals. P. oceanica immediately accumulated pollutants from the beginning of experiments; once contaminations ended, TE concentrations came back close to their original levels within 2 weeks, or at least showed a clear decrease. Posidonia leaves exhibited different uptake kinetics for many elements (Cr, Cu, Zn, Ag, Cd, Pb and Bi): the younger growing leaves incorporated chemicals more rapidly than the older ones. Rhizomes did not show any clear trend, except for Cu, Zn and Bi. These results demonstrate that Posidonia is a very sensitive sentinel to immediately delineate punctual pollutions similar to what might be measured in contaminated Mediterranean waters. The very good response of Posidonia leaves to pollutant short term expositions suggests their routine use in regularly scheduled monitoring programs. Nevertheless, to by-pass Posidonia leaves deciduous character and their capability to detoxify rapidly, long term accumulation recordings also necessitate below-ground tissues analyses. [less ▲]

Detailed reference viewed: 59 (10 ULg)