Faulkner Katelyn T, Robertson Mark P, Rouget Mathieu, Wilson John R U
Invasive Species Programme, South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa.
Centre for Invasion Biology, Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa.
PLoS One. 2017 Apr 5;12(4):e0173340. doi: 10.1371/journal.pone.0173340. eCollection 2017.
The global shipping network facilitates the transportation and introduction of marine and terrestrial organisms to regions where they are not native, and some of these organisms become invasive. South Africa was used as a case study to evaluate the potential for shipping to contribute to the introduction and establishment of marine and terrestrial alien species (i.e. establishment debt) and to assess how this varies across shipping routes and seasons. As a proxy for the number of species introduced (i.e. 'colonisation pressure') shipping movement data were used to determine, for each season, the number of ships that visited South African ports from foreign ports and the number of days travelled between ports. Seasonal marine and terrestrial environmental similarity between South African and foreign ports was then used to estimate the likelihood that introduced species would establish. These data were used to determine the seasonal relative contribution of shipping routes to South Africa's marine and terrestrial establishment debt. Additionally, distribution data were used to identify marine and terrestrial species that are known to be invasive elsewhere and which might be introduced to each South African port through shipping routes that have a high relative contribution to establishment debt. Shipping routes from Asian ports, especially Singapore, have a particularly high relative contribution to South Africa's establishment debt, while among South African ports, Durban has the highest risk of being invaded. There was seasonal variation in the shipping routes that have a high relative contribution to the establishment debt of the South African ports. The presented method provides a simple way to prioritise surveillance effort and our results indicate that, for South Africa, port-specific prevention strategies should be developed, a large portion of the available resources should be allocated to Durban, and seasonal variations and their consequences for prevention strategies should be explored further.
全球航运网络促进了海洋和陆地生物向非原生地区的运输和引入，其中一些生物成为入侵物种。南非被用作案例研究，以评估航运导致海洋和陆地外来物种引入和定殖（即定殖债务）的可能性，并评估这种情况在不同航运路线和季节中的变化。作为引入物种数量（即“定殖压力”）的替代指标，航运移动数据被用于确定每个季节从外国港口访问南非港口的船只数量以及港口之间的航行天数。然后利用南非与外国港口之间季节性的海洋和陆地环境相似性来估计引入物种定殖的可能性。这些数据被用于确定航运路线对南非海洋和陆地定殖债务的季节性相对贡献。此外，分布数据被用于识别已知在其他地方具有入侵性且可能通过对定殖债务有较高相对贡献的航运路线引入到每个南非港口的海洋和陆地物种。来自亚洲港口，尤其是新加坡的航运路线对南非的定殖债务有特别高的相对贡献，而在南非港口中，德班面临入侵的风险最高。对南非港口定殖债务有较高相对贡献的航运路线存在季节性变化。所提出的方法提供了一种简单的方式来确定监测工作的优先级，我们的结果表明，对于南非而言，应制定针对特定港口的预防策略，应将大部分可用资源分配给德班，并且应进一步探索季节性变化及其对预防策略的影响。
