The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jonny Beyer - One of the best experts on this subject based on the ideXlab platform.
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levels and trends of tributyltin tbt and Imposex in dogwhelk nucella lapillus along the norwegian coastline from 1991 to 2017
Marine Environmental Research, 2019Co-Authors: Merete Schoyen, N Green, Dag Oystein Hjermann, Lise Ann Tveiten, Bjornar Beylich, Sigurd Oxnevad, Jonny BeyerAbstract:The banning of organotin biocides, such as tributyltin (TBT), from use in marine antifouling paints is now leading to reproductive health recovery in marine gastropod populations all over the world. TBT induces so-called Imposex (superimposition of male sexual characters onto females) in certain marine gastropods, such as the common dogwhelk Nucella lapillus. In this publication, the results of the Norwegian TBT and Imposex monitoring in N. lapillus from the period 1991-2017 are presented. Significantly higher levels of TBT and Imposex were measured in coastal areas close to shipping lanes along most of the coast prior to 2008 than afterwards. Levels started declining after restrictions were imposed on the use of TBT in all antifouling paint applications, with a total ban in 2008. In 2017, no sign of Imposex was found in N. lapillus in any of the monitoring stations along the Norwegian coastline. Based on monitoring data shown herein, the importance of long-term biomonitoring and international chemical regulations, as well as the TBT and Imposex story in general, are discussed.
Merete Schoyen - One of the best experts on this subject based on the ideXlab platform.
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levels and trends of tributyltin tbt and Imposex in dogwhelk nucella lapillus along the norwegian coastline from 1991 to 2017
Marine Environmental Research, 2019Co-Authors: Merete Schoyen, N Green, Dag Oystein Hjermann, Lise Ann Tveiten, Bjornar Beylich, Sigurd Oxnevad, Jonny BeyerAbstract:The banning of organotin biocides, such as tributyltin (TBT), from use in marine antifouling paints is now leading to reproductive health recovery in marine gastropod populations all over the world. TBT induces so-called Imposex (superimposition of male sexual characters onto females) in certain marine gastropods, such as the common dogwhelk Nucella lapillus. In this publication, the results of the Norwegian TBT and Imposex monitoring in N. lapillus from the period 1991-2017 are presented. Significantly higher levels of TBT and Imposex were measured in coastal areas close to shipping lanes along most of the coast prior to 2008 than afterwards. Levels started declining after restrictions were imposed on the use of TBT in all antifouling paint applications, with a total ban in 2008. In 2017, no sign of Imposex was found in N. lapillus in any of the monitoring stations along the Norwegian coastline. Based on monitoring data shown herein, the importance of long-term biomonitoring and international chemical regulations, as well as the TBT and Imposex story in general, are discussed.
Tahani El Ayari - One of the best experts on this subject based on the ideXlab platform.
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Imposex incidence in stramonita haemastoma gastropoda muricidae from the mediterranean and atlantic coast after tributyltin global ban
Journal of Sea Research, 2018Co-Authors: Tahani El Ayari, Nicolas Bierne, Najoua Trigui El MenifAbstract:Abstract The development of male genital tract by female gastropods, or Imposex, can be caused by the tributyltin used in antifouling paints. A spatial survey of Imposex in the gastropod Stramonita haemastoma was conducted across five Western Mediterranean and eleven North-Eastern Atlantic sites, in order to monitor the effectiveness of the tributyltin regulation imposed in the International Maritime Organisation. Imposex still occurs in eight out of eleven Mediterranean sites and in three out of five Atlantic sites. Extreme values of Imposex incidence (I%) and degree (VDSI) were recorded in Tunisia, mainly in Bizerta channel (I% = 96.2%, VDSI = 0.96). However, the Relative Penis Length index (RPLI) was higher in Western Mediterranean sites where values varied between 0.56 in Algiers (Algeria) and 11.80 in Bouznika (Morocco). In the European sites, moderate to low Imposex level and degree were recorded. All the affected sites were below the Ecotoxicological Assessment Criteria (EAC) derived for TBT.
Heegu Choi - One of the best experts on this subject based on the ideXlab platform.
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temporal trends 2004 2009 of Imposex in rock shells thais clavigera collected along the korean coast associated with tributyltin regulation in 2003 and 2008
Archives of Environmental Contamination and Toxicology, 2013Co-Authors: Minkyu Choi, Hyobang Moon, Hyunseo Cho, Heegu ChoiAbstract:We investigated the temporal trend in contamination of butyltin compounds (BTs) along the Korean coast using Imposex and tributyltin (TBT) burden in gastropods (Thais clavigera) as a biomonitor. Thais clavigera were collected from 26 locations with different shipping activities between 2004 and 2009 after restrictions on TBT-based antifouling paints were imposed in Korea. In the present study, Imposex indices and TBT tissue concentrations significantly decreased over time from 2004 to 2009, confirming the effectiveness of TBT regulation. However, Imposex in 2009 samples was still found. Significantly high Imposex indices and TBT tissue residues were found in large ports containing commercial and ferry services compared with small ports and background areas. Imposex indices in background areas had decreased to zero, suggesting recovery from Imposex caused by BT contamination. These results suggest that recovery from TBT contamination occurs faster in areas with very low maritime activities than areas with high maritime activities.
Italo Braga Castro - One of the best experts on this subject based on the ideXlab platform.
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pugilina morio l a new Imposex exhibitor from south american estuarine environments approach for a non lethal method to evaluate Imposex
Bulletin of Environmental Contamination and Toxicology, 2012Co-Authors: Deyse De Azevedo, Cristina De Almeida Rochabarreira, Helena Matthewscascon, Italo Braga CastroAbstract:This is the first report on Imposex occurrence in Pugilina morio. Imposex levels in P. morio from Ceara River Estuary were assessed by a non-lethal method. The obtained Imposex parameters were: percentage = 37.1 %, female penis length index (FPLI) = 0.93 mm, relative penis length index (RPLI) = 6.5 %, and vas deferens sequence index (VDSI) = 1.0. Because Imposex is induced by tributyltin, and P. morio is widely distributed on the East coast of South America, the species can be used as a tributyltin contamination sentinel in these estuaries. Additionally, a non-lethal method of evaluating Imposex minimized the impact on the population of P. morio from sample collection, as all organisms were returned to the environment.
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transplant bioassay induces different Imposex responses in two species of the genus stramonita
Marine Biology Research, 2012Co-Authors: Italo Braga Castro, Marcos Antônio Fernandez, Cristina De Almeida Rochabarreira, Gregorio BigattiAbstract:A bioassay to study differential specific responses in Imposex development due to marine organotin pollution was done by transplanting specimens of the gastropods Stramonita haemastoma and Stramonita rustica from an Imposex-free area to a marina with high marine traffic inside a ship repair yard, a place where local populations of S. haemastoma were known to show high indices of Imposex. Three hundred sexually mature, Imposex-free specimens of each species were kept in cages for 120 days, and samples of 30 individuals were periodically analysed for Imposex development. Shell length, penis length and vas deferens development were recorded and Imposex development indices (% Imposex, RPLI and VDSI) were calculated. Our results indicated that Imposex induction in S. haemastoma is faster and more sensitive than in S. rustica. Imposex incidence in S. haemastoma could be a useful tool for monitoring marine pollution by organotin compounds in harbours along the Brazilian coast.
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butyltin compounds and Imposex levels in ecuador
Archives of Environmental Contamination and Toxicology, 2012Co-Authors: Italo Braga Castro, Maria Fernanda Arroyo, Patricia Gomes Costa, Gilberto FillmannAbstract:The first appraisal of butyltins (BT) contamination linked with Imposex incidence in the Pacific coast of South America was performed in the current study. Imposex occurrence was analyzed in three muricid species (Thais biserialis, T. brevidentata, and T. kiosquiformis) distributed along 14 sites from the coastal areas of Ecuador. All studied muricids species showed Imposex, which was observed in 11 out of 14 sites. The highest Imposex levels were observed in T. kiosquiformis collected inside the Gulf of Guayaquil [relative penis length index (RPLI) 9.0–40.7], whereas RPLI values for T. biserialis and T. brevidentata ranged from 4.0 to 26.1 and 0.0 to 1.9, respectively. Additionally, BT compounds [tributyltin (TBT), dibutylin (DBT), and monobutylin (MBT)] were determined in surface sediments collected in 6 of the sites (main harbor areas), and values ranged between 12.7 and 99.5 ng Sn g−1 (dry weight) for TBT, 1.8 and 54.4 ng Sn g−1 for DBT, and 44 and 340 ng Sn g−1 for MBT. Although BT degradation indexes suggested an aged input of TBT, the high Imposex levels detected in the current study suggest that international restrictions on TBT based antifouling paints were still not effective in Ecuador. Considering that the southern coast, especially nearby harbors inside the Gulf of Guayaquil, have shown to be contaminated by BTs, a combination of T. kiosquiformis and T. biserialis (the most sensitive species) can be used for future biomonitoring of Ecuador coastal areas.
