Biological introduction risks from shipping in a warming Arctic

Abstract

Summary1. 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. 2. 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. 3. Ships discharging ballast water in Svalbard carried high densities of zooplankton (mean 1522 AE 335 SE individuals m À3 ), 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 AE 67 SE individuals m À3 ), despite five of the eight ships exchanging ballast water en route.4. 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) 8Á5 climate scenario, however, modelled suitability will favour colonization for six species. 5. 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 biogeo- 2016, 53, 340-349 doi: 10.1111/1365-2664.12566 graphic 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. Journal of Applied Ecology

Invasion Science: A Horizon Scan of Emerging Challenges and Opportunities

“…Prospective access to new energy resources, raw materials, and a major shipping route has attracted keen interest from many nations including China, India, and South Korea. Propagule supply to Arctic habitats will increase dramatically [50,51], challenging efforts to protect northern fisheries and endemic biodiversity under increasing disturbance from alien species. Transport on ships' hulls of fouling organisms could ultimately pose a greater threat than ballast water discharge, if the latter vector abates in importance owing to recent ratification of a global convention requiring treatment of ballast water.…”

Climate change opens new frontiers for marine species in the Arctic: Current trends and future invasion risks

“…The establishment success of the species might be attributed to a lack of native species to provide biological resistance (Koberstein, 2013). The species has spread rapidly along the west and south coasts of Iceland since the initial detection of the species in 2003 (Gunnarsson et al, 2007) and may continue to spread as climate change is expected to expand the extent of suitable habitat for this NIS in Arctic waters (Ware et al, 2016).…”

“…Ballast water of commercial ships is an important transfer mechanism for aquatic NIS in the Arctic (Chan, MacIsaac, & Bailey, 2015;Sokolov, Strelkova, Manushin, & Sennikov, 2016;Ware et al, 2016).…”

“…No NIS introduced via the live food trade were successful established in Arctic waters.Not surprisingly, vessels are the leading pathway for both single and multipathway introductions. Therefore, vessels have, and will likely continue to provide ample opportunities for the transfer of aquatic NIS to the Arctic.Ballast water of commercial ships is an important transfer mechanism for aquatic NIS in the Arctic(Chan, MacIsaac, & Bailey, 2015;Sokolov, Strelkova, Manushin, & Sennikov, 2016;Ware et al, 2016).The risk of ballast-mediated introductions, however, is expected to be mitigated by the implementation of ballast water management systems (BWMS). More recently, the commercial use of northern shipping routes is increasingly viable due to drastic reductions in Arctic sea ice cover(Melia, Haines, & Hawkins, 2016).…”

Survival of ship biofouling assemblages during and after voyages to the Canadian Arctic

“…Arctic coastal environments are under unprecedented threats from NIS because of climate change, resource development, and expanded Arctic shipping (Miller and Ruiz 2014; Ware et al 2014, 2016). Rising sea surface temperature in the Arctic over the past three decades has resulted in retreating sea ice (Hoegh-Guldberg and Bruno 2010) and opening of waterways and shipping channels such as the Northern Sea Route and the Northwest Passage (Smith and Stephenson 2013; Pizzolato et al 2014; Miller and Ruiz 2014).…”