Luc Bruyn | Research Institute for Nature and Forest (original) (raw)
Papers by Luc Bruyn
BMC ecology, 2014
Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speci... more Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci. We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of ef...
Environmental Toxicology and Chemistry, 2003
We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the mi... more We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the midge Chironomus riparius. Sediment ingestion rate was determined for one week. After 24 h the gut content remained constant, indicating that equilibrium was reached between sediment ingestion and sediment elimination. These data were used to account for radiocesium present in the gut in subsequent uptake experiments. Reference sediment was equilibrated with solutions containing different concentrations of potassium: 1, 10, 100, and 1,000 M. Adsorption of 137 Cs to the sediment was investigated. Three different radiocesium levels (0.3, 0.6, and 1.2 KBq/ml) were applied at the four different potassium levels. In all cases more than 94% of all radiocesium was adsorbed to the sediment within 48 h. The sediment, equilibrated with the four different potassium levels, was spiked with a constant amount of 296 Bq/ml 137 Cs. Accumulation by midge larvae was followed for one week, and subsequently elimination was followed for another week. No significant differences in radiocesium levels in midge larvae among the treatments were found after one week of exposure. However, using a one-compartment accumulation model, a small but significant effect of potassium in water and sediment on the uptake and elimination rate constants (k a and k e ) was found. These results indicate that although differences were rather small, radiocesium accumulation decreased with increasing potassium level in the sediment.
EUROSLA Yearbook, 2006
... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, e... more ... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, extraversion scores in a normal population approximate a normal curve with averages ranging between 6 and 8 (Sanderman, Arrindell, Ranchor, Eysenck and Eysenck 1995, Matthews ...
Zoological Journal of the Linnean Society, 1994
EUROSLA Yearbook, 2006
... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, e... more ... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, extraversion scores in a normal population approximate a normal curve with averages ranging between 6 and 8 (Sanderman, Arrindell, Ranchor, Eysenck and Eysenck 1995, Matthews ...
Freshwater Biology, 2003
1. We investigated the relationship between geographical distribution and ecological tolerance wi... more 1. We investigated the relationship between geographical distribution and ecological tolerance within the ancient asexual family Darwinulidae. Distribution maps were compiled based on data from the literature, the Non-marine Ostracod Distribution in Europe database and personal collections. Ecological tolerance was assessed experimentally by exposing individual ostracods to a combination of eight different salinities (range from 0 to 30 g L )1 ) and three different temperatures (10, 20 and 30°C). 2. The type species of the family, Darwinula stevensoni, is ubiquitous and cosmopolitan; the two species Penthesilenula brasiliensis and Microdarwinula zimmeri also have an intercontinental distribution. Two other darwinulid species tested here (Vestalenula molopoensis and P. aotearoa) are known only from their type localities. The latter is also true for most extant darwinulids. 3. Darwinula stevensoni and P. brasiliensis had a broad salinity tolerance, tolerating distilled water and also salinity up to 25-30 g L )1 , whereas the maximum salinity tolerance of V. molopoensis was 12 g L )1 and of P. aotearoa, 20 g L )1 . 4. The results indicate that both ecological specialists and generalists, as well as intermediate forms, exist in the Darwinulidae and that taxa with the broadest ecological tolerance also have the widest distribution.
Dit hoofdstuk focust op de effecten van klimaatveranderingen op de natuur in Vlaanderen. Het is o... more Dit hoofdstuk focust op de effecten van klimaatveranderingen op de natuur in Vlaanderen. Het is opgebouwd rond volgende hoofdlijnen: • De ontwikkelde Vlaamse klimaatscenario’s wijzen eenduidig op een stijging van de gemiddelde omgevingstemperatuur tegen 2100 met 1,5°C tot 4,4°C in de winter en met 2,4°C tot 7,2°C in de zomer en op meer neerslag tijdens de winter. • De meeste klimaatscenario’s tonen een daling van de gemiddelde zomerneerslag voor Vlaanderen. • Achttien soorten broedvogels en zestien soorten dagvlinders, waaronder een aantal algemene soorten, lopen een verhoogd risico om tegen 2100 uit Vlaanderen te verdwijnen door de temperatuurstijging. • Mogelijk kunnen nieuwe broedvogel- en dagvlindersoorten zich in Vlaanderen vestigen dankzij de temperatuurstijging. Dit hoofdstuk is integraal te downloaden van http://www.natuurrapport.be/sites/default/files/NARA-2009-02_klimaat.pdf
The role of vegetation and soil factors on the biodiversity of two soil dwelling, saprophagous, f... more The role of vegetation and soil factors on the biodiversity of two soil dwelling, saprophagous, fly families (Sphaeroceridae and Lonchopteridae) in a heathland ecosystem were investigated. The fly community is primarily affected by soil humidity and the amount of organic matter while the vegetation structure and species composition only indirectly influence the fly communities. There was no correlation between plant species richness and the fly diversity indices. Based on our results and literature data, we hypothesise that the direct effects of the vegetation is more evident for herbivorous insects than for species that do not feed on plants. The investigated families show a clear response to microhabitat differences in the soil factors, which makes them promising indicators for soil health and as tool for monitoring environmental changes.
Environmental Toxicology and Chemistry, 2003
We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the mi... more We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the midge Chironomus riparius. Sediment ingestion rate was determined for one week. After 24 h the gut content remained constant, indicating that equilibrium was reached between sediment ingestion and sediment elimination. These data were used to account for radiocesium present in the gut in subsequent uptake experiments. Reference sediment was equilibrated with solutions containing different concentrations of potassium: 1, 10, 100, and 1,000 M. Adsorption of 137 Cs to the sediment was investigated. Three different radiocesium levels (0.3, 0.6, and 1.2 KBq/ml) were applied at the four different potassium levels. In all cases more than 94% of all radiocesium was adsorbed to the sediment within 48 h. The sediment, equilibrated with the four different potassium levels, was spiked with a constant amount of 296 Bq/ml 137 Cs. Accumulation by midge larvae was followed for one week, and subsequently elimination was followed for another week. No significant differences in radiocesium levels in midge larvae among the treatments were found after one week of exposure. However, using a one-compartment accumulation model, a small but significant effect of potassium in water and sediment on the uptake and elimination rate constants (k a and k e ) was found. These results indicate that although differences were rather small, radiocesium accumulation decreased with increasing potassium level in the sediment.
Canadian Journal of Botany, 1998
BMC Ecology, 2014
Background: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecol... more Background: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci. Results: We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of effective long-distance seed dispersal and low levels of adaptive divergence. At least 15% of the assigned individuals likely originated from among-population dispersal events with dispersal distances up to 220 km. Six (1.3%) 'outlier' loci, potentially reflecting local adaptation to habitat-type, were identified with high statistical support. Of these, only one (0.22%) was a replicated outlier in multiple independent dune-fen population comparisons and thus possibly reflecting truly parallel divergence. Signals of adaptation in response to habitat type were most evident at the scale of individual populations. Conclusions: The findings of this study suggest that the homogenizing effect of effective long-distance seed dispersal may overwhelm divergent selection associated to habitat type in fen orchids in Northwest Europe.
Canadian Journal of Botany, 1998
Science of The Total Environment, 2015
Metal oxide nanoparticles are increasingly being produced and will inevitably end up in the aquat... more Metal oxide nanoparticles are increasingly being produced and will inevitably end up in the aquatic environment. Up till now, most papers have studied individual nanoparticle effects. However, the implementation of these data into a risk assessment tool, needed to characterise their risk to the aquatic environment, is still largely lacking. Therefore, aquatic species sensitivity distributions (SSDs) were constructed for ZnO and CuO nanoparticles and 5% hazard concentrations (HC5) were calculated in this study. The effect of individual nanoparticles on these SSDs was estimated by comparison with bulk SSDs. Additionally, the effect of nanoparticle dynamics (aggregation and dissolution) was considered by evaluating the effect of aggregate size on the toxicity, by estimation of the dissolved fraction and comparison with SSDs for ZnCl2 and CuCl2 inorganic salt. Bacteria, protozoa, yeast, rotifera, algae, nematoda, crustacea, hexapoda, fish and amphibia species were included in the analysis. The results show that algae (Zn) and crustacea (Zn, Cu) are the most sensitive species when exposed to the chemicals. Similar acute sensitivity distributions were obtained for ZnO nanoparticles (HC5: 0.06 with 90% confidence interval: 0.03-0.15mg Zn/l; 43 data points), bulk ZnO (HC5: 0.06 with CI: 0.03-0.20mg Zn/l; 23dps) and ZnCl2 (HC5: 0.03 with CI: 0.02-0.05mg Zn/l; 261dps). CuO nanoparticles (HC5: 0.15 with CI: 0.05-0.47mg Cu/l; 43dps) are more toxic than the bulk materials (HC5: 6.19 with CI: 2.15-38.11mg Cu/l; 12dps) but less toxic than CuCl2 (HC5: 0.009 with CI: 0.007-0.012mg Cu/l; 594dps) to aquatic species. However, the combined dissolution and SSD results indicate that the toxicity of these nanoparticles is mainly caused by dissolved metal ions. Based on the available information, no current risk of these nanoparticles to the aquatic environment is expected.
Science of The Total Environment, 2012
We investigated the accumulation of persistent organic pollutants in damselfly larvae (Ischnura e... more We investigated the accumulation of persistent organic pollutants in damselfly larvae (Ischnura elegans) in sixteen ponds in Flanders (Belgium), widely differing in the surrounding land use. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB) were measured. From all targeted PBDE-congeners, only three congeners (IUPAC nos. 47, 99, 100) were above the limit of quantification (LOQ). The ∑PBDE concentrations ranged from b LOQ up to 0.51 ng g − 1 ww. From the targeted PCB-congeners, thirteen were detectable (IUPAC nos. 95, 99, 101, 105, 118, 138, 149, 153, 156, 170, 180, 183, and 187). A high variation in ∑PCB concentrations was observed between the ponds, ranging from b LOQ (0.67 ng g − 1 ww) up to 9.91 ng g − 1 ww in the damselflies from the pond at Sijsele. In all investigated Flemish ponds, p,p'-DDE concentrations were > LOQ (0.20 ng g − 1 ww) with values up to 3.30 ng g − 1 ww in the pond at Hamme. In fifteen ponds, the HCB concentrations were >LOQ (0.05 ng g − 1 ww) with values up to 0.24 ng g − 1 ww. For the available data in the literature a comparison with different species was done for some of the sampled ponds. The monitored ponds can be separated in three groups based on their contamination. The first group is characterised by a relative low POP content (∑PBDEs, ∑PCBs, HCB). Group 2 contained more HCB and p,p'-DDE than the overall mean while this was the case for PBDEs and PCBs in group 3. The vectors of both contaminated groups are situated nearly perpendicular which is suggesting a different pollution sources.
Journal of the North American Benthological Society, 2000
... over 700 km, including 200 km of ocean between the estuaries of the Brisbane and Mary rivers.... more ... over 700 km, including 200 km of ocean between the estuaries of the Brisbane and Mary rivers. ... For the 1992 sample, three ad-ditional enzymes were run; PeptidaseC (PEPC, IECC no ... The test is non-parametric (Manly 1985) and can be used on ordinal and continuous data, as ...
Aquatic Toxicology, 2014
The present study measured various pesticides and trace metals, together with sublethal effect bi... more The present study measured various pesticides and trace metals, together with sublethal effect biomarkers (lipid, protein and glycogen levels, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities) in damselfly larvae (Ischnura elegans) at sixteen sampling sites in Flanders (Belgium). Four pesticides (chloridazon, dichlorvos, terbutylazine, metolachlor), some of them hardly measurable in surface water, and all trace metals were above the limit of quantification in damselfly tissue. A principal component analysis (PCA) on the accumulated pollutant concentrations returned five pollutant axes explaining 85.8% of the total variation. Based on these PCA-axes a hierarchical cluster analysis revealed that the 16 sampled ponds could be classified in 7 groups. Increasing dichlorvos levels in the animals resulted in a lower body mass. Body mass was negatively correlated with GST and AChE activities, lipid and glycogen levels. The present findings provide evidence of toxicity-induced sublethal stress of dichlorvos accumulation in natural populations of I. elegans.
Archiv für Hydrobiologie, 2005
... Arch. Hydrobiol., Suppl. 58: 97206. WISSINGER, SA, BROwN, WS & JANNOT, JE (2003): Caddis... more ... Arch. Hydrobiol., Suppl. 58: 97206. WISSINGER, SA, BROwN, WS & JANNOT, JE (2003): Caddisfly life histories along permanence gradients in high-altitude wetlands in Colorado (USA). Fresh-wat. Biol. 48: 255270. ...
BMC ecology, 2014
Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speci... more Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci. We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of ef...
Environmental Toxicology and Chemistry, 2003
We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the mi... more We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the midge Chironomus riparius. Sediment ingestion rate was determined for one week. After 24 h the gut content remained constant, indicating that equilibrium was reached between sediment ingestion and sediment elimination. These data were used to account for radiocesium present in the gut in subsequent uptake experiments. Reference sediment was equilibrated with solutions containing different concentrations of potassium: 1, 10, 100, and 1,000 M. Adsorption of 137 Cs to the sediment was investigated. Three different radiocesium levels (0.3, 0.6, and 1.2 KBq/ml) were applied at the four different potassium levels. In all cases more than 94% of all radiocesium was adsorbed to the sediment within 48 h. The sediment, equilibrated with the four different potassium levels, was spiked with a constant amount of 296 Bq/ml 137 Cs. Accumulation by midge larvae was followed for one week, and subsequently elimination was followed for another week. No significant differences in radiocesium levels in midge larvae among the treatments were found after one week of exposure. However, using a one-compartment accumulation model, a small but significant effect of potassium in water and sediment on the uptake and elimination rate constants (k a and k e ) was found. These results indicate that although differences were rather small, radiocesium accumulation decreased with increasing potassium level in the sediment.
EUROSLA Yearbook, 2006
... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, e... more ... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, extraversion scores in a normal population approximate a normal curve with averages ranging between 6 and 8 (Sanderman, Arrindell, Ranchor, Eysenck and Eysenck 1995, Matthews ...
Zoological Journal of the Linnean Society, 1994
EUROSLA Yearbook, 2006
... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, e... more ... 220 Siska van Daele, Alex Housen, Michel Pierrard and Luc Debruyn ... In practice, however, extraversion scores in a normal population approximate a normal curve with averages ranging between 6 and 8 (Sanderman, Arrindell, Ranchor, Eysenck and Eysenck 1995, Matthews ...
Freshwater Biology, 2003
1. We investigated the relationship between geographical distribution and ecological tolerance wi... more 1. We investigated the relationship between geographical distribution and ecological tolerance within the ancient asexual family Darwinulidae. Distribution maps were compiled based on data from the literature, the Non-marine Ostracod Distribution in Europe database and personal collections. Ecological tolerance was assessed experimentally by exposing individual ostracods to a combination of eight different salinities (range from 0 to 30 g L )1 ) and three different temperatures (10, 20 and 30°C). 2. The type species of the family, Darwinula stevensoni, is ubiquitous and cosmopolitan; the two species Penthesilenula brasiliensis and Microdarwinula zimmeri also have an intercontinental distribution. Two other darwinulid species tested here (Vestalenula molopoensis and P. aotearoa) are known only from their type localities. The latter is also true for most extant darwinulids. 3. Darwinula stevensoni and P. brasiliensis had a broad salinity tolerance, tolerating distilled water and also salinity up to 25-30 g L )1 , whereas the maximum salinity tolerance of V. molopoensis was 12 g L )1 and of P. aotearoa, 20 g L )1 . 4. The results indicate that both ecological specialists and generalists, as well as intermediate forms, exist in the Darwinulidae and that taxa with the broadest ecological tolerance also have the widest distribution.
Dit hoofdstuk focust op de effecten van klimaatveranderingen op de natuur in Vlaanderen. Het is o... more Dit hoofdstuk focust op de effecten van klimaatveranderingen op de natuur in Vlaanderen. Het is opgebouwd rond volgende hoofdlijnen: • De ontwikkelde Vlaamse klimaatscenario’s wijzen eenduidig op een stijging van de gemiddelde omgevingstemperatuur tegen 2100 met 1,5°C tot 4,4°C in de winter en met 2,4°C tot 7,2°C in de zomer en op meer neerslag tijdens de winter. • De meeste klimaatscenario’s tonen een daling van de gemiddelde zomerneerslag voor Vlaanderen. • Achttien soorten broedvogels en zestien soorten dagvlinders, waaronder een aantal algemene soorten, lopen een verhoogd risico om tegen 2100 uit Vlaanderen te verdwijnen door de temperatuurstijging. • Mogelijk kunnen nieuwe broedvogel- en dagvlindersoorten zich in Vlaanderen vestigen dankzij de temperatuurstijging. Dit hoofdstuk is integraal te downloaden van http://www.natuurrapport.be/sites/default/files/NARA-2009-02_klimaat.pdf
The role of vegetation and soil factors on the biodiversity of two soil dwelling, saprophagous, f... more The role of vegetation and soil factors on the biodiversity of two soil dwelling, saprophagous, fly families (Sphaeroceridae and Lonchopteridae) in a heathland ecosystem were investigated. The fly community is primarily affected by soil humidity and the amount of organic matter while the vegetation structure and species composition only indirectly influence the fly communities. There was no correlation between plant species richness and the fly diversity indices. Based on our results and literature data, we hypothesise that the direct effects of the vegetation is more evident for herbivorous insects than for species that do not feed on plants. The investigated families show a clear response to microhabitat differences in the soil factors, which makes them promising indicators for soil health and as tool for monitoring environmental changes.
Environmental Toxicology and Chemistry, 2003
We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the mi... more We studied the effect of potassium on the uptake of radiocesium from sediment by larvae of the midge Chironomus riparius. Sediment ingestion rate was determined for one week. After 24 h the gut content remained constant, indicating that equilibrium was reached between sediment ingestion and sediment elimination. These data were used to account for radiocesium present in the gut in subsequent uptake experiments. Reference sediment was equilibrated with solutions containing different concentrations of potassium: 1, 10, 100, and 1,000 M. Adsorption of 137 Cs to the sediment was investigated. Three different radiocesium levels (0.3, 0.6, and 1.2 KBq/ml) were applied at the four different potassium levels. In all cases more than 94% of all radiocesium was adsorbed to the sediment within 48 h. The sediment, equilibrated with the four different potassium levels, was spiked with a constant amount of 296 Bq/ml 137 Cs. Accumulation by midge larvae was followed for one week, and subsequently elimination was followed for another week. No significant differences in radiocesium levels in midge larvae among the treatments were found after one week of exposure. However, using a one-compartment accumulation model, a small but significant effect of potassium in water and sediment on the uptake and elimination rate constants (k a and k e ) was found. These results indicate that although differences were rather small, radiocesium accumulation decreased with increasing potassium level in the sediment.
Canadian Journal of Botany, 1998
BMC Ecology, 2014
Background: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecol... more Background: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci. Results: We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of effective long-distance seed dispersal and low levels of adaptive divergence. At least 15% of the assigned individuals likely originated from among-population dispersal events with dispersal distances up to 220 km. Six (1.3%) 'outlier' loci, potentially reflecting local adaptation to habitat-type, were identified with high statistical support. Of these, only one (0.22%) was a replicated outlier in multiple independent dune-fen population comparisons and thus possibly reflecting truly parallel divergence. Signals of adaptation in response to habitat type were most evident at the scale of individual populations. Conclusions: The findings of this study suggest that the homogenizing effect of effective long-distance seed dispersal may overwhelm divergent selection associated to habitat type in fen orchids in Northwest Europe.
Canadian Journal of Botany, 1998
Science of The Total Environment, 2015
Metal oxide nanoparticles are increasingly being produced and will inevitably end up in the aquat... more Metal oxide nanoparticles are increasingly being produced and will inevitably end up in the aquatic environment. Up till now, most papers have studied individual nanoparticle effects. However, the implementation of these data into a risk assessment tool, needed to characterise their risk to the aquatic environment, is still largely lacking. Therefore, aquatic species sensitivity distributions (SSDs) were constructed for ZnO and CuO nanoparticles and 5% hazard concentrations (HC5) were calculated in this study. The effect of individual nanoparticles on these SSDs was estimated by comparison with bulk SSDs. Additionally, the effect of nanoparticle dynamics (aggregation and dissolution) was considered by evaluating the effect of aggregate size on the toxicity, by estimation of the dissolved fraction and comparison with SSDs for ZnCl2 and CuCl2 inorganic salt. Bacteria, protozoa, yeast, rotifera, algae, nematoda, crustacea, hexapoda, fish and amphibia species were included in the analysis. The results show that algae (Zn) and crustacea (Zn, Cu) are the most sensitive species when exposed to the chemicals. Similar acute sensitivity distributions were obtained for ZnO nanoparticles (HC5: 0.06 with 90% confidence interval: 0.03-0.15mg Zn/l; 43 data points), bulk ZnO (HC5: 0.06 with CI: 0.03-0.20mg Zn/l; 23dps) and ZnCl2 (HC5: 0.03 with CI: 0.02-0.05mg Zn/l; 261dps). CuO nanoparticles (HC5: 0.15 with CI: 0.05-0.47mg Cu/l; 43dps) are more toxic than the bulk materials (HC5: 6.19 with CI: 2.15-38.11mg Cu/l; 12dps) but less toxic than CuCl2 (HC5: 0.009 with CI: 0.007-0.012mg Cu/l; 594dps) to aquatic species. However, the combined dissolution and SSD results indicate that the toxicity of these nanoparticles is mainly caused by dissolved metal ions. Based on the available information, no current risk of these nanoparticles to the aquatic environment is expected.
Science of The Total Environment, 2012
We investigated the accumulation of persistent organic pollutants in damselfly larvae (Ischnura e... more We investigated the accumulation of persistent organic pollutants in damselfly larvae (Ischnura elegans) in sixteen ponds in Flanders (Belgium), widely differing in the surrounding land use. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB) were measured. From all targeted PBDE-congeners, only three congeners (IUPAC nos. 47, 99, 100) were above the limit of quantification (LOQ). The ∑PBDE concentrations ranged from b LOQ up to 0.51 ng g − 1 ww. From the targeted PCB-congeners, thirteen were detectable (IUPAC nos. 95, 99, 101, 105, 118, 138, 149, 153, 156, 170, 180, 183, and 187). A high variation in ∑PCB concentrations was observed between the ponds, ranging from b LOQ (0.67 ng g − 1 ww) up to 9.91 ng g − 1 ww in the damselflies from the pond at Sijsele. In all investigated Flemish ponds, p,p'-DDE concentrations were > LOQ (0.20 ng g − 1 ww) with values up to 3.30 ng g − 1 ww in the pond at Hamme. In fifteen ponds, the HCB concentrations were >LOQ (0.05 ng g − 1 ww) with values up to 0.24 ng g − 1 ww. For the available data in the literature a comparison with different species was done for some of the sampled ponds. The monitored ponds can be separated in three groups based on their contamination. The first group is characterised by a relative low POP content (∑PBDEs, ∑PCBs, HCB). Group 2 contained more HCB and p,p'-DDE than the overall mean while this was the case for PBDEs and PCBs in group 3. The vectors of both contaminated groups are situated nearly perpendicular which is suggesting a different pollution sources.
Journal of the North American Benthological Society, 2000
... over 700 km, including 200 km of ocean between the estuaries of the Brisbane and Mary rivers.... more ... over 700 km, including 200 km of ocean between the estuaries of the Brisbane and Mary rivers. ... For the 1992 sample, three ad-ditional enzymes were run; PeptidaseC (PEPC, IECC no ... The test is non-parametric (Manly 1985) and can be used on ordinal and continuous data, as ...
Aquatic Toxicology, 2014
The present study measured various pesticides and trace metals, together with sublethal effect bi... more The present study measured various pesticides and trace metals, together with sublethal effect biomarkers (lipid, protein and glycogen levels, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities) in damselfly larvae (Ischnura elegans) at sixteen sampling sites in Flanders (Belgium). Four pesticides (chloridazon, dichlorvos, terbutylazine, metolachlor), some of them hardly measurable in surface water, and all trace metals were above the limit of quantification in damselfly tissue. A principal component analysis (PCA) on the accumulated pollutant concentrations returned five pollutant axes explaining 85.8% of the total variation. Based on these PCA-axes a hierarchical cluster analysis revealed that the 16 sampled ponds could be classified in 7 groups. Increasing dichlorvos levels in the animals resulted in a lower body mass. Body mass was negatively correlated with GST and AChE activities, lipid and glycogen levels. The present findings provide evidence of toxicity-induced sublethal stress of dichlorvos accumulation in natural populations of I. elegans.
Archiv für Hydrobiologie, 2005
... Arch. Hydrobiol., Suppl. 58: 97206. WISSINGER, SA, BROwN, WS & JANNOT, JE (2003): Caddis... more ... Arch. Hydrobiol., Suppl. 58: 97206. WISSINGER, SA, BROwN, WS & JANNOT, JE (2003): Caddisfly life histories along permanence gradients in high-altitude wetlands in Colorado (USA). Fresh-wat. Biol. 48: 255270. ...