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- Hilvarsson, Annelie, 1978, et al.
(författare)
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Bioaccumulation of the new antifoulant medetomidine in marine organisms
- 2009
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Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136. ; 68:1, s. 19-24
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Tidskriftsartikel (refereegranskat)abstract
- Biofouling is a huge problem globally and new alternative antifoulants are presently being investigated. one candidate is medetomidine, a commonly used sedative in veterinary medicine, which has been shown to effectively prevent settlement of barnacles. The purpose of this study was to measure uptake, elimination and bioconcentration of medetomidine in Mytilus edulis, Abra nitida, Crangon crangon and periphyton communities to evaluate the risk of bioaccumulation in the marine environment. Bioconcentration factors (BCF) and bioaccumulation factors (BAF) were used to assess the bioaccumulation. The calculations of these factors were based on the distribution of the radiolabelled medetomidine. BCF for C. crangon was 2.8 while M. edulis had a BCF of 134 and the periphyton communities' BCF was 1195 l/kg fresh weight (FW). The concentration of medetomidine in the animals reached steady state after 24-48 h for all test systems except for A. nitida, which never stabilised enough to calculate a bioaccumulation factor (BAF). Elimination from the organism's tissues was rapid for three of the test systems with half-lives between 1 and 24 h, A. nitida had a half-life of 96-120 h. This study demonstrates that the bioconcentration and bioaccumulation of medetomidine differs between aquatic organisms and that microalgal communities in the form of periphyton have the highest bioconcentration factor of the organisms tested. (C) 2009 Elsevier Ltd. All rights reserved.
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| 2. |
- Ohlauson, Cecilia, et al.
(författare)
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A comparison of toxicant-induced succession for five antifouling compounds on marine periphyton in SWIFT microcosms
- 2014
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Ingår i: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 30:1, s. 41-50
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Tidskriftsartikel (refereegranskat)abstract
- Five antifouling biocides, chlorothalonile, dichlofluanide, medetomidine, tolylfluanide, and zinc pyrithione, were evaluated regarding their effect on the composition of the periphyton community and the subsequent toxicant-induced succession (TIS). The periphyton communities were exposed in a semi-static setting for 96 h using a SWIFT microcosm. As a measure of community composition, pigment profiles from the exposed communities were used as effect indicators and compared with unexposed parts of the same community using the Bray-Curtis dissimilarity index. Chlorothalonile caused changes in the community starting at 85 μg l-1 while dichlofluanide had no effect even at the highest concentrations used, 810 μg l-1. The related substance tolylfluanide only affected the community composition at 2700 μg l-1. Medetomidine had a different response curve with a small effect on the community composition at 0.8 μg l-1 which then disappeared only to reappear at 240 μg l-1. Zinc pyrithione had the largest effect on the periphyton community with changes starting at 10 μg l-1 and no detectable pigments at 100 μg l-1. The changes in the community composition for the five substances were also compared using multidimensional scaling. When all substances were analyzed and plotted together, chlorothalonile, dichlofluanide, medetomidine, and tolylfluanide showed surprisingly similar effects compared to zinc pyrithione that gave very different TIS. However, when only chlorothalonile, dichlofluanide, and tolylfluanide were plotted together, clear differences in TIS between the three toxicants were revealed. Dichlofluanide only induced small effects, while concentration-dependent TIS trajectories for chlorothalonile and tolylfluanide took off in opposite directions indicating very different responses of the periphyton communities. This study demonstrates that substances with a similar chemical structure and mechanisms of action can have different effects on the community composition. With the exception of zinc pyrithione, none of the recorded effect levels were at concentrations reported from marine environments so far. © 2013 © 2013 Taylor & Francis.
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| 3. |
- Ohlauson, Cecilia, et al.
(författare)
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Short-term effects of medetomidine on photosynthesis and protein synthesis in periphyton, epipsammon and plankton communities in relation to predicted environmental concentrations
- 2012
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Ingår i: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 28:5, s. 491-499
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Tidskriftsartikel (refereegranskat)abstract
- Medetomidine is a new antifouling substance, highly effective against barnacles. As part of a thorough ecotoxicological evaluation of medetomidine, its short-term effects on algal and bacterial communities were investigated and environmental concentrations were predicted with the MAMPEC model. Photosynthesis and bacterial protein synthesis for three marine communities, viz. periphyton, epipsammon and plankton were used as effect indicators, and compared with the predicted environmental concentrations (PECs). The plankton community showed a significant decrease in photosynthetic activity of 16% at 2 mg l(-1) of medetomidine, which was the only significant effect observed. PECs were estimated for a harbor, shipping lane and marina environment using three different model scenarios (MAMPEC default, Baltic and OECD scenarios). The highest PEC of 57 ng l(-1), generated for a marina with the Baltic scenario, was at least 10,000-fold lower than the concentration that significantly decreased photosynthetic activity. It is concluded that medetomidine does not cause any acute toxic effects on bacterial protein synthesis and only small acute effects on photosynthesis at high concentrations in marine microbial communities. It is also concluded that the hazard from medetomidine on these processes is low since the effect levels are much lower than the highest PEC.
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