Rey Anaïs, Basurko Oihane C, Rodriguez-Ezpeleta Naiara
Marine Research Division AZTI Sukarrieta Spain.
Ecol Evol. 2020 Feb 7;10(5):2452-2465. doi: 10.1002/ece3.6071. eCollection 2020 Mar.
Monitoring introduction and spread of nonindigenous species via maritime transport and performing risk assessments require port biological baseline surveys. Yet, the comprehensiveness of these surveys is often compromised by the large number of habitats present in a port, the seasonal variability, and the time-consuming morphological approach used for taxonomic identification. Metabarcoding represents a promising alternative for rapid comprehensive port biological baseline surveys, but its application in this context requires further assessments.We applied metabarcoding (based on barcodes of the cytochrome c oxidase subunit I and of the 18S ribosomal RNA gene) to 192 port samples collected (a) from diverse habitats (water column-including environmental DNA and zooplankton, sediment, and fouling structures), (b) at different sites (from inner to outer estuary), and iii) during the four seasons of the year.By comparing the biodiversity metrics derived from each sample group, we show that each sampling method resulted in a distinct community profile and that environmental DNA alone cannot substitute for organismal sampling, and that, although sampling at different seasons and locations resulted in higher observed biodiversity, operational results can be obtained by sampling selected locations and seasons.By assessing the taxonomic composition of the samples, we show that metabarcoding data allowed the detection of previously recorded nonindigenous species as well as to reveal presence of new ones, even if in low abundance. Our comprehensive assessment of metabarcoding for port biological baseline surveys sets the basics for cost-effective, standardized, and comprehensive monitoring of nonindigenous species and for performing risk assessments in ports. This development will contribute to the implementation of the recently entered into force International Convention for the Control and Management of Ships' Ballast Water and Sediments.
通过海上运输监测非本地物种的引入和扩散并进行风险评估需要开展港口生物基线调查。然而，这些调查的全面性常常受到港口存在的大量栖息地、季节变化以及用于分类鉴定的耗时形态学方法的影响。宏条形码技术是快速全面开展港口生物基线调查的一种有前景的替代方法，但其在这种情况下的应用需要进一步评估。我们将宏条形码技术（基于细胞色素c氧化酶亚基I和18S核糖体RNA基因的条形码）应用于192个港口样本，这些样本采集于：(a) 不同栖息地（水柱——包括环境DNA和浮游动物、沉积物以及污损结构）；(b) 不同地点（从河口内到河口外）；(c) 一年中的四个季节。通过比较每个样本组得出的生物多样性指标，我们发现每种采样方法都产生了独特的群落概况，环境DNA alone无法替代生物体采样，并且尽管在不同季节和地点采样会带来更高的观察到的生物多样性，但通过对选定的地点和季节进行采样也能获得可操作的结果。通过评估样本的分类组成，我们发现宏条形码数据能够检测到先前记录的非本地物种，也能揭示新物种的存在，即便其丰度较低。我们对用于港口生物基线调查的宏条形码技术的全面评估为经济高效、标准化且全面地监测非本地物种以及在港口进行风险评估奠定了基础。这一进展将有助于实施最近生效的《国际船舶压载水和沉积物控制与管理公约》。
