Data from: Biological introduction threats from shipping in a warming Arctic

Several decades of research on invasive marine species have yielded a broad understanding of the nature of species invasion mechanisms and associated threats globally. However, this is not true of the Arctic, a region where ongoing climatic changes may promote species invasion. Here, we evaluated risks associated with non-indigenous propagule loads discharged with ships' ballast water to the high-Arctic archipelago, Svalbard, as a case study for the wider Arctic. We sampled and identified transferred propagules using traditional and DNA barcoding techniques. We then assessed the suitability of the Svalbard coast for non-indigenous species under contemporary and future climate scenarios using ecophysiological models based on critical temperature and salinity reproductive thresholds. Ships discharging ballast water in Svalbard carried high densities of zooplankton (mean 1522 ± 335 SE individuals m−3), predominately comprised of indigenous species. Ballast water exchange did not prevent non-indigenous species introduction. Non-indigenous coastal species were present in all except one of 16 ballast water samples (mean 144 ± 67 SE individuals m−3), despite five of the eight ships exchanging ballast water en route. Of a total of 73 taxa, 36 species including 23 non-indigenous species were identified. Of those 23, sufficient data permitted evaluation of the current and future colonization potential for eight widely known invaders. With the exception of one of these species, modelled suitability indicated that the coast of Svalbard is unsuitable presently; under the 2100 Representative Concentration Pathway (RCP) 8·5 climate scenario, however, modelled suitability will favour colonization for six species. Synthesis and applications. We show that current ballast water management practices do not prevent non-indigenous species from being transferred to the Arctic. Consequences of these shortcomings will be shipping-route dependent, but will likely magnify over time: our models indicate future conditions will favour the colonization of non-indigenous species Arctic-wide. Invasion threats will be greatest where shipping transfers organisms across biogeographic realms, and for these shipping routes ballast water treatment technologies may be required to prevent impacts. Our results also highlight critical gaps in our understanding of ballast water management efficacy and prioritization. Thereby, our study provides an agenda for research and policy development.

数十年来，针对入侵海洋物种的研究已形成了对全球范围内物种入侵机制本质及相关威胁的全面认知。然而，这一认知并不适用于北极地区——该区域正在发生的气候变化或会推动物种入侵。本研究以高北极群岛斯瓦尔巴（Svalbard）为研究对象，评估了船舶压载水排放携带的非本土繁殖体负载所带来的入侵风险，以此作为整个北极地区的案例研究。我们采用传统方法与DNA条形码（DNA barcoding）技术对转运的繁殖体进行采样与鉴定。随后，基于临界温度与盐度繁殖阈值构建的生理生态模型，我们评估了当代与未来气候情景下斯瓦尔巴海岸对非本土物种的适宜性。在斯瓦尔巴海域排放压载水的船舶，其压载水中浮游动物（zooplankton）密度极高（平均1522 ± 335标准误个体·m⁻³），且绝大多数为本土物种。压载水交换并未阻止非本土物种的引入：尽管8艘船舶中有5艘在航程中开展了压载水交换，但16个压载水样本中仅1个未检出非本土沿海物种，其余样本的平均密度为144 ± 67标准误个体·m⁻³。本次研究共鉴定出73个类群，其中包含23种非本土物种在内的36个物种被成功检出。在这23种非本土物种中，有8种广为人知的入侵物种可获取足够数据，用于评估其当前与未来的定殖潜力。除其中1个物种外，模型预测当前斯瓦尔巴海岸尚不具备适宜物种定殖的环境条件；但在2100年典型浓度路径（RCP）8.5的气候情景下，模型预测将有6个物种具备适宜定殖的环境条件。研究总结与应用启示。本研究证实，当前的压载水管理措施无法阻止非本土物种被转运至北极地区。此类管理缺陷所引发的后果将因航运航线而异，但会随时间推移不断加剧：我们的模型显示，未来北极全域的环境条件将更有利于非本土物种的定殖。当航运跨生物地理区系转运生物时，入侵威胁将最为突出，此类航运航线需采用压载水处理技术以规避生态影响。此外，本研究结果还凸显了当前在压载水管理效能与优先级认知方面存在的关键缺口。综上，本研究为相关领域的研究与政策制定提供了明确的行动方向。