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

Abstract

Climate change and increased anthropogenic activities are expected to elevate the potential of introducing nonindigenous species (NIS) into the Arctic. Yet, the knowledge base needed to identify gaps and priorities for NIS research and management is limited. Here, we reviewed primary introduction events to each ecoregion of the marine Arctic realm to identify temporal and spatial patterns, likely source regions of NIS, and the putative introduction pathways. We included 54 introduction events representing 34 unique NIS. The rate of NIS discovery ranged from zero to four species per year between 1960 and 2015. The Iceland Shelf had the greatest number of introduction events (n = 14), followed by the Barents Sea (n = 11), and the Norwegian Sea (n = 11). Sixteen of the 54 introduction records had no known origins. The majority of those with known source regions were attributed to the Northeast Atlantic and the Northwest Pacific, 19 and 14 records, respectively. Some introduction events were attributed to multiple possible pathways. For these introductions, vessels transferred the greatest number of aquatic NIS (39%) to the Arctic, followed by natural spread (30%) and aquaculture activities (25%). Similar trends were found for introductions attributed to a single pathway. The phyla Arthropoda and Ochrophyta had the highest number of recorded introduction events, with 19 and 12 records, respectively. Recommendations including vector management, horizon scanning, early detection, rapid response, and a pan-Arctic biodiversity inventory are considered in this paper. Our study provides a comprehensive record of primary introductions of NIS for marine environments in the circumpolar Arctic and identifies knowledge gaps and opportunities for NIS research and management. Ecosystems worldwide will face dramatic changes in the coming decades due to global change. Our findings contribute to the knowledge base needed to address two aspects of global change-invasive species and climate change.

Keywords: alien species; aquaculture; climate warming; fisheries; invasion pathways; invasive species; knowledge gap; nonindigenous species; shipping; vessels.

Figure 1

Map illustrating the Large Marine Ecosystems of the Arctic (Arctic LMEs) as defined by the Arctic Council's Protection of the Arctic Marine Environment Working Group (PAME, 2013). ID numbers 1 = Faroe Islands, 2 = Iceland Shelf, 3 = Greenland Sea East‐Greenland, 4 = Norwegian Sea, 5 = Barents Sea, 6 = Kara Sea, 7 = Laptev Sea, 8 = East Siberian Sea, 9 = East Bering Sea, 10 = Aleutian Islands, 11 = West Bering Sea, 12 = Northern Bering Chukchi Sea, 13 = Central Arctic Ocean, 14 = Beaufort Sea, 15 = Canadian High Arctic‐North Greenland, 16 = Canadian East Arctic‐West Greenland, 17 = Hudson Bay, and 18 = Labrador‐Newfoundland. Also shown are the total number of introduction events (n = 54) and the population status of NIS in each introduced region

Figure 2

Map depicting the Food and Agriculture Organization of the United Nations (FAO) fishing regions (FAO, 2018) used to describe the source(s) of NIS introduced in the marine Arctic. ID numbers 18 = Arctic Sea, 21 = Northwest Atlantic, 27 = Northeast Atlantic, 31 = West Central Atlantic, 34 = East Central Atlantic, 37 = Mediterranean and Black Sea, 41 = Southwest Atlantic, 47 = Southeast Atlantic, 48 = Antarctic Atlantic, 51 = Western Indian Ocean, 57 = Eastern Indian Ocean, 58 = Antarctic and Southern Indian Ocean, 61 = Northwest Pacific, 67 = Northeast Pacific, 71 = Western Central Pacific, 77 = Eastern Central Pacific, 81 Southwest Pacific, 87 = Southeast Pacific, and 88 = Antarctic Pacific. Also shown are the total number of introductions originated from each FAO area (n = 49, excluding introduction events with no known source regions) and the population status of the corresponding NIS in the introduced regions

Figure 3

Number of new NIS discovered annually (a) and cumulative number of NIS detected with the best‐fitted curve (b) in the marine Arctic from 1960 to 2015. Data shown represent the earliest reliable date of first report in the Arctic for 34 NIS

Figure 4

Analysis of primary introduction events attributed to a single pathway (a) and multiple pathways (b). Also shown is the population status of NIS at introduced sites in the marine Arctic

Figure 5

Number of NIS detected in Arctic waters by phylum and population status. Data shown represent 54 introduction events involving 34 NIS

Figure 6

Annual mean water temperature at 5 m depth along the current route from Rotterdam to Yokohama using the Suez canal (~11,200 nautical miles; left panels) and when using the Northern Sea Route (~6,500 nautical miles; right panels). The y‐axes in these panels are not to scale. Panels a and b show the temperature trends at the North Sea and the Barents Sea, which are the locations with the greatest increase in water temperature over time (dashed lines in panels c and d) along the current and the northern routes, respectively. For panels a and b, blue line = extracted temperature values along the dashed lines in panels c and d, and black line = temperature trend