Effects of ice-associated stressors and pollutants on the Arctic marine cryosphere

北极的生物区和非生物区都存在着一系列持久性化学污染物，包括雪和冰。这些化学品包括多氯联苯和滴滴涕等较老的遗留污染物，以及一系列物理化学性质截然不同的较新的“新兴”污染物。北极物理和生物环境的迅速变化正在改变污染物的路径和命运，使生物暴露和影响难以预测；实际上，北极的变化可能正在改变污染物的生物暴露，甚至加剧这种情况。这项提议的目的是对海冰(特别是第一年海冰--北极变暖的主要冰类)在化学污染物积累和随后向海洋食物网底部释放方面的作用提供一个机械和定量的了解。初步证据表明，海冰中存在一些较新的污染物，其浓度类似于温带沿海海洋，我们需要知道造成这种情况的原因，以及一旦污染物在冬季结束时解冻时释放出来，可能会暴露在生物群中。阐明这一过程并了解海洋冰雪中化学品的命运和行为有助于形成全球一级的化学品管理战略，特别是如果北极冰冻圈的变化也改变了冰和周围海水中的营养物质供应。将在北极观察的污染物和营养过程将得到人造海冰实验的支持。我们计划利用实地和实验室研究来研究这一主题，并利用这些研究来模拟对低等海洋食物网的影响，研究营养物质和污染物的可用性是否有联系，以及它们对海冰栖息地功能的影响。

An array of persistent chemical pollutants are present in the Arctic in both biota and abiotic compartments, including snow and ice. These chemicals include older legacy contaminants such as PCBs and DDT, well as an array of newer 'emerging' contaminants with contrasting physical-chemical properties. Rapid changes to the physical and biological environment in the Arctic are changing the pathways and fate of pollutants, making biological exposure and impact difficult to predict; indeed changes to the Arctic may be altering the biological exposure to contaminants and even exacerbating it. The purpose of this proposal is to provide a mechanistic and quantitative understanding on the role of sea ice (particularly first year sea ice - the dominant ice type in a warmer Arctic) in the accumulation and subsequent release of chemical contaminants to the base of the marine foodweb. Preliminary evidence indicates that some newer contaminants are present in sea ice at concentrations akin to temperate coastal seas and we need to know the reasons for this, plus the likely exposure to biota once contaminants are released during ice break up and melt at the end of winter. Elucidating this process and understanding the fate and behaviour of chemicals in marine ice and snow can help shape chemical management strategies at the global level, particularly if changes to the Arctic cryosphere are also altering nutirent availability in ice and surrounding seawater. The contaminant and nutrient processes to be observed in the Arctic will be supported by artificial sea ice experiments. We plan to investigate this topic using field and laboratory studies and use these to model effects on the lower marine foodweb, examining whether nutrient and contaminant availability are linked and their impact on sea ice habitat functioning.