Marine Biology Research Group, Ghent University, Ghent, Belgium.
Sci Rep. 2021 Oct 7;11(1):19996. doi: 10.1038/s41598-021-99441-3.
Deep seabed mining is potentially imminent in the Clarion Clipperton Fracture Zone (CCFZ; northeast Pacific). Seabed collectors will remove polymetallic nodules and the surrounding surface sediments, both inhabited by meiofauna, along their path. To determine potential impacts of polymetallic nodule removal, we investigated the importance of nodule presence for the abundance, composition and diversity of sediment meiofauna, and evaluated the existence and composition of nodule crevice meiofauna in the Global Sea Mineral Resources (GSR) exploration contract area. Nodule-free and nodule-rich sediments displayed high biodiversity with many singletons and doubletons, potentially representing rare taxa. Nodule presence negatively influenced sediment meiofaunal abundances but did not markedly affect taxonomic composition or diversity. This is the first report on CCFZ nodule crevice meiofauna, whose abundance related positively to nodule dimensions. Though dominated by the same taxa, nodules and sediments differed regarding the taxonomic and trophic composition of the meio- and nematofauna. Nevertheless, there were no taxa endemic to the nodule crevices and nodule crevice meiofauna added only little to total small-scale (~ cm) meiofaunal abundance and diversity. We formulated environmental management recommendations at the contract area and regional (CCFZ) scale related to sampling effort, set-aside preservation and monitoring areas, and potential rehabilitation measures.
深海采矿在克拉里昂-克利珀顿断裂区（CCFZ；东北太平洋）可能即将发生。海底采集器将沿着其路径清除多金属结核和周围的表层沉积物，而这些沉积物都有中海洋生物栖息。为了确定多金属结核清除的潜在影响，我们研究了结核存在对沉积物中海洋生物丰度、组成和多样性的重要性，并评估了全球海洋矿产资源（GSR）勘探合同区中结核裂缝中海洋生物的存在和组成。无结核和结核丰富的沉积物表现出高生物多样性，有许多单种和双种生物，可能代表稀有分类群。结核的存在对沉积物中海洋生物的丰度有负面影响，但对分类组成或多样性没有明显影响。这是首次报道 CCFZ 结核裂缝中海洋生物的情况，其丰度与结核尺寸呈正相关。尽管结核和沉积物的分类和营养组成存在差异，但它们都由相同的类群主导。然而，结核裂缝中没有特有类群，结核裂缝中的中海洋生物对总小规模（~cm）中海洋生物的丰度和多样性的贡献很小。我们在合同区和区域（CCFZ）范围内制定了与采样努力、预留保存和监测区以及潜在恢复措施相关的环境管理建议。
