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.

Here we analyze the potential of black carbon (BC) and oil-inclusive models to explain in situ sorption of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), organochlorine pesticides (OCP), polychlorobiphenyls (PCB), polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF) to harbor sediments. Such models are important to understand bioavailability and mobility limitations of these chemicals in the aquatic environment. Separate BC- or oil-inclusive models have been described before. However, it is unclear whether oil could dominate in situ sorption in sediments that also contain BC, and whether the relative importance of phases would differ for different compounds. A BC- and oil-inclusive model was evaluated against chemical data and measured sediment characteristics. Parameter uncertainty was assessed using Monte Carlo simulations. Fitted model parameters were consistent with literature data and were satisfactory from a statistical as well as a chemical perspective. Sorption to oil was strong, proportional to octanol-water partitioning (Log K(ow)) and of similar magnitude for OCP, PCB, PCDD, and PCDF. For PAH a single oil sorption coefficient was found. Oil dominated sorption only for PCBs, at oil levels above 50-250 mg oil/kg sediment. BC dominated sorption of most other compounds, especially high molecular PAHs, PCDD, and PCDFs.

No abstract

De Directie van Wageningen Marine Research is niet aansprakelijk voor gevolgschade, noch voor schade welke voortvloeit uit toepassingen van de resultaten van werkzaamheden of andere gegevens verkregen van Wageningen Marine Research opdrachtgever vrijwaart Wageningen Marine Research van aanspraken van derden in verband met deze toepassing. Dit rapport is vervaardigd op verzoek van de opdrachtgever hierboven aangegeven en is zijn eigendom. Niets uit dit rapport mag weergegeven en/of gepubliceerd worden, gefotokopieerd of op enige andere manier gebruikt worden zonder schriftelijke toestemming van de opdrachtgever.

Chlorine efficacy as a biocide for ballast water treatment was investigated under cold-and warm-water temperatures across winter and summer seasons. Freshwater phytoplankton samples were collected and acclimated under in situ environmental conditions ranging from 2 to 22°C. Samples were exposed to seven chlorine treatments (from 0.02 to 5.0 ppm), in addition to a control (0.0 ppm). Free-chlorine concentrations, phytoplankton abundance, and photosynthetic efficiency were measured up to 48 h following treatment. After 4 h of treatment at concentrations less than 0.22 ppm, phytoplankton densities were reduced by more than 50%, without cell resurgence. Similar reduction was recorded immediately after exposure when chlorine concentrations were higher than 3.0 ppm. After 8 h, free chlorine neared 0.0 ppm for initial chlorine concentrations below 1.2 ppm, irrespective of temperature regime. Winter phytoplankton exhibited slightly lower mortality to chlorine exposure regardless of the temperature, although they also exhibited lower photosynthetic efficiency. Despite a general absence of significant effect of temperature on the chlorine decay, our results suggest that higher doses of chlorine or longer exposure times may be required during winter to achieve full treatment effect. Tests at large scales are needed to further confirm these findings.Résumé : L'efficacité du chlore comme biocide pour le traitement de l'eau de ballast a été étudiée dans des conditions d'eau chaude et froide, en été et en hiver. Des échantillons de phytoplancton d'eau douce ont été prélevés et acclimatés dans des conditions ambiantes allant de 2°C à 22°C. Les échantillons ont été exposés à sept traitements au chlore (de 0,02 ppm à 5,0 ppm), en plus d'un traitement témoin (0,0 ppm). Les concentrations de chlore libre, ainsi que l'abondance et le rendement photosynthétique du phytoplancton ont été mesurés jusqu'à 48 h après le traitement. Après 4 h de traitement à des concentrations de moins de 0,22 ppm, les densités de phytoplancton avaient baissé de plus de 50 % sans résurgence de cellules. Une baisse semblable a été observée immédiatement après l'exposition quand les concentrations de chlore étaient supérieures à 3,0 ppm. Après 8 h, la concentration de chlore libre s'approchait de 0,0 ppm pour des concentrations initiales de chlore inférieures à 1,2 ppm, peu importe le régime thermique. Le phytoplancton hivernal présentait une mortalité légèrement plus faible découlant de l'exposition au chlore, quelle que soit la température, mais son rendement photosynthétique était aussi plus faible. Malgré l'absence générale d'effet significatif de la température sur la décomposition du chlore, nos résultats donnent à penser que des doses plus élevées de chlore ou de plus longues durées d'exposition pourraient être nécessaires durant l'hiver pour que le traitement soit pleinement efficace. Des essais à grande échelle sont nécessaires pour confirmer ces résultats. [Traduit par la Rédaction]