...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Estuarine Coastal and Shelf Science >Complex patterns in fish - sediment mercury concentrations in a contaminated estuary: The influence of selenium co-contamination?
【24h】

Complex patterns in fish - sediment mercury concentrations in a contaminated estuary: The influence of selenium co-contamination?

机译：鱼中复杂的形态-污染河口中的沉积物汞浓度：硒共污染的影响？

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Environmental mercury (Hg) loads do not always correspond to Hg concentrations in resident fish and selenium (Se) presence has been reported to play a pivotal role in mitigating Hg bioaccumulation. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in sediments and a benthic fish species (Platycephalus bassensis) from a contaminated estuary (Derwent Estuary, Tasmania). Elevated sediment concentrations of Se did not result in increased Se concentrations in fish, but low concentrations of Se were associated with increased MeHg bioavailability (% MeHg) from sediments to fish. Where MeHg (≈99% of total Hg) concentration in fish was high Se uptake also increased, indicating that maintaining positive Se:Hg ratios may reduce the toxicity of MeHg. MeHg was detectable in sediments throughout the estuary, and a molar excess of THg over Se suggested that there was insufficient Se to prevent methylation from the sediments. Se:Hg ratios of less than 1.0 in sediments, coupled with high %MeHg fraction and high biotic sediment accumulation factors for MeHg (BSAF_(MeHg)). Indicated that the lower region of the Derwent Estuary could be a hotspot for Hg methylation, despite having significantly lower THg concentrations. In contrast, Hg bioavailability to fish from sediments close to the source may be reduced by both inorganic Hg species complexation and lower methylation rates. There was a strong association between THg and Se in estuarine sediments, suggesting that Se plays an important role in sediment Hg cycling and should be a key consideration in any future assessments of Hg methylation, bioavailability and bioaccumulation.
机译：环境汞（Hg）的负载量并不总是与常驻鱼类中的Hg浓度相对应，据报道，硒（Se）的存在在减轻汞的生物蓄积中起关键作用。测量了受污染河口（塔斯马尼亚州德温特河口）的沉积物和底栖鱼类（Platycephalus bassensis）中的总汞（THg），甲基汞（MeHg）和硒浓度。沉积物中硒的浓度升高不会导致鱼类中硒的含量增加，但是低浓度的硒与从沉积物到鱼类的MeHg生物利用度（％MeHg）增加相关。鱼类中的MeHg（约占总Hg的99％）浓度较高时，Se的吸收也会增加，这表明维持正的Se：Hg比值可能会降低MeHg的毒性。在整个河口的沉积物中都可以检测到MeHg，THg相对于Se摩尔过量，表明Se不足以防止沉积物中的甲基化。沉积物中的Se：Hg比率小于1.0，再加上MeHg（BSAF_（MeHg））的高％MeHg分数和高生物沉积物积累因子。表明德文特河口的下部区域可能是Hg甲基化的热点，尽管THg浓度明显较低。相反，无机Hg物种的络合和较低的甲基化率可能会降低来自源头附近沉积物的鱼类的Hg生物利用度。河口沉积物中THg和Se之间有很强的联系，这表明Se在沉积物Hg循环中起着重要作用，并且应该在将来对Hg甲基化，生物利用度和生物蓄积性的任何评估中都应重点考虑。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号