In the past, the dog whelk Nucella lapillus (Mollusca, Gastropoda, Muricidae) used to be a common... more In the past, the dog whelk Nucella lapillus (Mollusca, Gastropoda, Muricidae) used to be a common species on jetties and groynes along the Belgian coast. During the seventies, the species became increasingly rare and the last Belgian specimen observed in situ was found in 1981. The extinction of the species is attributed to the use of paintings containing tributyltin (TBT) on the hulls of ships as antifouling protection. TBT dilutes in seawater and, even at extremely low concentration, sterilizes dog whelks. Since 1990, the use of Tributyltin (TBT) was restricted to ships smaller than 25 m; in 2003, it was totally forbidden and in 2008 old TBT paintings had to be removed from ship hulls. As a consequence the concentration in TBT of seawater presumably decreased in Belgian waters. On November 17th, 2012, several living adult dog whelks and 40 to 50 spawns ofthat species were observed on the concrete blocks of the western jetty of Zeebrugge harbour, indicating recolonization of the sp...
We discuss the results of a Malaisetrap sampling campaign at Schave (Deinze, Oost-Vlaanderen) in ... more We discuss the results of a Malaisetrap sampling campaign at Schave (Deinze, Oost-Vlaanderen) in the valley of the Zeverenbeek, a former influent of the Leie. Characteristic for this study site are a thick layer of peat, the presence of some seepage areas, a structure-rich vegetation due to grazing and a mosaic of vegetation types. Ten taxonomic specialists contributed to the identification of the collected material and in total we could identify 217 insect species belonging to 33 families and 22 spider species belonging to 9 families. Among them are many habitat specialists of wet grasslands, swamps, wet brushwood, valleys and seepage areas.
During the summer of 2011 a Malaisetrap was set up along a brackish ditch in the Jeronimuspolder ... more During the summer of 2011 a Malaisetrap was set up along a brackish ditch in the Jeronimuspolder in Sint-Laureins to make an inventory of invertebrates. On the banks of the ditch a lot of Scirpus maritimus L. grows and a salty meadow is bordering the ditch. A total of 150 species were identified, belonging to 18 insect and 5 spider families. Seven species are halophilous or halobiont, comprising Stratiomyidae (two species), Dolichopodidae (three species), Muscidae (one species) and Cicadellidae (one species). Four other species are not true halophilous, but tolerate high salt concentrations. Amongst the non-halophilous species there are habitat specialists of reed vegetations, marshes and oligotrophic grasslands. Therefore it is important to maintain the patchwork of micro(habitats) for the conservation of the invertebrate diversity in the studied area. The Malaise trap sampling provided the first observation in Belgium for two Muscidae : Helina maculipennis and Coenosia antennata, ...
ABSTRACT The invasive bryozoan, Tricellaria inopinata d'Hondt & Occhipinti Ambrog... more ABSTRACT The invasive bryozoan, Tricellaria inopinata d'Hondt & Occhipinti Ambrogi, 1985 was first recorded in European waters in the early 1980's and has since been reported from 166 locations from the Mediterranean Sea to the north-east Atlantic coastline. This species is typically associated with human activity, including commercial and recreational vessels and aquaculture, where it has been found in abundance on boat hulls and propellers, floating pontoons and structures associated with shellfish cultivation. Tricellaria inopinata has a high tolerance to a wide range of salinities and temperatures, although following the harsh winter of 2010, populations disappeared in Germany suggesting that this species is near the northern limit of its range under current climatic conditions. It is expected to continue to disperse though, throughout the Mediterranean, English Channel, North and Celtic Seas.
In the past, the dog whelk Nucella lapillus (Mollusca, Gastropoda, Muricidae) used to be a common... more In the past, the dog whelk Nucella lapillus (Mollusca, Gastropoda, Muricidae) used to be a common species on jetties and groynes along the Belgian coast. During the seventies, the species became increasingly rare and the last Belgian specimen observed in situ was found in 1981. The extinction of the species is attributed to the use of paintings containing tributyltin (TBT) on the hulls of ships as antifouling protection. TBT dilutes in seawater and, even at extremely low concentration, sterilizes dog whelks. Since 1990, the use of Tributyltin (TBT) was restricted to ships smaller than 25 m; in 2003, it was totally forbidden and in 2008 old TBT paintings had to be removed from ship hulls. As a consequence the concentration in TBT of seawater presumably decreased in Belgian waters. On November 17th, 2012, several living adult dog whelks and 40 to 50 spawns ofthat species were observed on the concrete blocks of the western jetty of Zeebrugge harbour, indicating recolonization of the sp...
We discuss the results of a Malaisetrap sampling campaign at Schave (Deinze, Oost-Vlaanderen) in ... more We discuss the results of a Malaisetrap sampling campaign at Schave (Deinze, Oost-Vlaanderen) in the valley of the Zeverenbeek, a former influent of the Leie. Characteristic for this study site are a thick layer of peat, the presence of some seepage areas, a structure-rich vegetation due to grazing and a mosaic of vegetation types. Ten taxonomic specialists contributed to the identification of the collected material and in total we could identify 217 insect species belonging to 33 families and 22 spider species belonging to 9 families. Among them are many habitat specialists of wet grasslands, swamps, wet brushwood, valleys and seepage areas.
During the summer of 2011 a Malaisetrap was set up along a brackish ditch in the Jeronimuspolder ... more During the summer of 2011 a Malaisetrap was set up along a brackish ditch in the Jeronimuspolder in Sint-Laureins to make an inventory of invertebrates. On the banks of the ditch a lot of Scirpus maritimus L. grows and a salty meadow is bordering the ditch. A total of 150 species were identified, belonging to 18 insect and 5 spider families. Seven species are halophilous or halobiont, comprising Stratiomyidae (two species), Dolichopodidae (three species), Muscidae (one species) and Cicadellidae (one species). Four other species are not true halophilous, but tolerate high salt concentrations. Amongst the non-halophilous species there are habitat specialists of reed vegetations, marshes and oligotrophic grasslands. Therefore it is important to maintain the patchwork of micro(habitats) for the conservation of the invertebrate diversity in the studied area. The Malaise trap sampling provided the first observation in Belgium for two Muscidae : Helina maculipennis and Coenosia antennata, ...
ABSTRACT The invasive bryozoan, Tricellaria inopinata d'Hondt & Occhipinti Ambrog... more ABSTRACT The invasive bryozoan, Tricellaria inopinata d'Hondt & Occhipinti Ambrogi, 1985 was first recorded in European waters in the early 1980's and has since been reported from 166 locations from the Mediterranean Sea to the north-east Atlantic coastline. This species is typically associated with human activity, including commercial and recreational vessels and aquaculture, where it has been found in abundance on boat hulls and propellers, floating pontoons and structures associated with shellfish cultivation. Tricellaria inopinata has a high tolerance to a wide range of salinities and temperatures, although following the harsh winter of 2010, populations disappeared in Germany suggesting that this species is near the northern limit of its range under current climatic conditions. It is expected to continue to disperse though, throughout the Mediterranean, English Channel, North and Celtic Seas.
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Papers by Hans De Blauwe
8. Reports Insect Trips by Hans De Blauwe