Ocean acidification increases copper toxicity differentially in two key marine invertebrates with distinct acid-base responses.
Ocean acidification increases copper toxicity differentially in two key marine invertebrates with distinct acid-base responses.
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DOI：
10.1038/srep21554
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发表时间：
2016-02-22
影响因子：
4.6
通讯作者：
Wilson RW
中科院分区：
文献类型：
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作者：
Lewis C;Ellis RP;Vernon E;Elliot K;Newbatt S;Wilson RW
预计海洋酸化将通过改变许多pH敏感金属的生物利用度和潜在毒性，间接影响生活在受污染沿海环境中的生物群。在这里，我们表明，OA（pH值7.71; pCO 2 1480 μatm）显着增加的毒性反应，全球沿海污染物（铜~0.1 μM）在两个关键的底栖物种;贻贝（紫贻贝）和紫海胆（Paracentrotus lividus）。贻贝表现出细胞外酸中毒响应OA和铜单独增强在联合曝光。与此相反，海胆保持细胞外液的pH值下OA积累碳酸氢盐，但表现出轻微的pH值在响应铜单独或与OA。重要的是，与对照条件（pH 8.14; pCO 2 470 μatm）相比，两种物种在OA下铜诱导的DNA和脂质损伤显著更大。然而，这种DNA损伤的增加是海胆比贻贝低四倍，这表明海胆的内部酸碱调节可能会大大减轻这种OA诱导的铜毒性作用的大小。因此，OA下金属毒性的变化可能不纯粹是由海水中的金属形态所驱动的，并且可能比单一压力源或单一物种的研究所表明的更加多样化。这对今后的环境管理战略具有重要意义。
Ocean acidification (OA) is expected to indirectly impact biota living in contaminated coastal environments by altering the bioavailability and potentially toxicity of many pH-sensitive metals. Here, we show that OA (pH 7.71; pCO2 1480 μatm) significantly increases the toxicity responses to a global coastal contaminant (copper ~0.1 μM) in two keystone benthic species; mussels (Mytilus edulis) and purple sea urchins (Paracentrotus lividus). Mussels showed an extracellular acidosis in response to OA and copper individually which was enhanced during combined exposure. In contrast, urchins maintained extracellular fluid pH under OA by accumulating bicarbonate but exhibited a slight alkalosis in response to copper either alone or with OA. Importantly, copper-induced damage to DNA and lipids was significantly greater under OA compared to control conditions (pH 8.14; pCO2 470 μatm) for both species. However, this increase in DNA-damage was four times lower in urchins than mussels, suggesting that internal acid-base regulation in urchins may substantially moderate the magnitude of this OA-induced copper toxicity effect. Thus, changes in metal toxicity under OA may not purely be driven by metal speciation in seawater and may be far more diverse than either single-stressor or single-species studies indicate. This has important implications for future environmental management strategies.