Faculty of Biosciences and Aquaculture, Nord University, Universitetsalléen 11, 8026 Bodø, Norway.
Faculty of Biosciences and Aquaculture, Nord University, Universitetsalléen 11, 8026 Bodø, Norway.
Sci Total Environ. 2024 Nov 20;952:175968. doi: 10.1016/j.scitotenv.2024.175968. Epub 2024 Sep 1.
With increasing socio-economic importance of the rare earth elements and yttrium (REY), Norway has laid out plans for REY mining, from land-based to deep-sea mining, thereby enhancing REY mobility in the marine ecosystem. Little is known about associated environmental consequences, especially in the deep ocean. We explored the toxicity and modes of action of a light (Nd), medium (Gd) and heavy (Yb) REY-Cl at four concentrations (3, 30, 300, and 3000 μg L) in the Arcto-boreal deep-sea amphipod Tmetonyx cicada. At the highest concentration, REY solubility was limited and increased with atomic weight (Nd < Gd < Yb). Lethal effects were practically restricted to this treatment, with the lighter elements being more acutely toxic than Yb (from ∼50 % mortality in the Gd-group at dissolved 689-504 μg L to <20 % in the Yb-group at ca. 2000 μg L), which could be a function of bioavailability. All three REY induced hyperactivity at the low-medium concentrations. Delving into the transcriptome of T. cicada allowed us to determine a whole array of potential (neurotoxic) mechanisms underlying this behaviour. Gd induced the vastest response, affecting serotonin-synthesis; sphingolipid-synthesis; the renin-angiotensin system; mitochondrial and endoplasmic reticulum functioning (Gd, Nd); and lysosome integrity (Gd, Yb); as well as the expression of hemocyanin, potentially governing REY-uptake (Gd, Yb). While Nd and Yb shared only few pathways, suggesting a link between mode of action and atomic weight/radius, almost all discussed mechanisms imply the disruption of organismal Ca-homeostasis. Despite only fragmental genomic information available for crustaceans to date, our results provide novel insight into the toxicophysiology of REY in marine biota. The neurotoxic/behavioural effects in T. cicada at concentrations with potential environmental relevance warn about the possibility of bottom-up ecological consequences in mining exposed fjords and deep-sea ecosystems, calling for follow-up studies and regulatory measures prior to the onset of REY mining in Norway.
随着稀土元素和钇（REY）的社会经济重要性不断增加，挪威已经制定了从陆地到深海采矿的计划，从而提高了海洋生态系统中 REY 的流动性。然而，人们对相关的环境后果知之甚少，尤其是在深海中。我们在北极-北方深海片脚类动物 Tmetonyx cicada 中，探索了四种浓度（3、30、300 和 3000μg/L）的轻（Nd）、中（Gd）和重（Yb）REY-Cl 的毒性和作用模式。在最高浓度下，REY 的溶解度有限，且随着原子量的增加而增加（Nd<Gd<Yb）。在这种处理下，致死效应实际上受到限制，较轻的元素比 Yb 更具急性毒性（在溶解的 689-504μg/L 的 Gd 组中，约有 50%的死亡率，而在约 2000μg/L 的 Yb 组中则低于 20%），这可能是生物利用度的函数。所有三种 REY 在中低浓度下都会引起过度活动。深入研究 T. cicada 的转录组，使我们能够确定一系列潜在的（神经毒性）机制，这些机制是导致这种行为的原因。Gd 诱导的反应最大，影响了血清素合成、神经酰胺合成、肾素-血管紧张素系统、线粒体和内质网功能（Gd、Nd）；溶酶体完整性（Gd、Yb）；以及血蓝蛋白的表达，可能控制着 REY 的摄取（Gd、Yb）。虽然 Nd 和 Yb 仅共享少数途径，表明作用模式和原子量/半径之间存在联系，但几乎所有讨论的机制都暗示了生物体钙稳态的破坏。尽管迄今为止，甲壳类动物的基因组信息仍然很零碎，但我们的研究结果为海洋生物群中 REY 的毒理学提供了新的见解。在具有潜在环境相关性的浓度下，T. cicada 表现出的神经毒性/行为效应警告人们，在挪威开始开采稀土元素之前，采矿业暴露的峡湾和深海生态系统可能会产生自下而上的生态后果，需要进行后续研究和采取监管措施。
