Marine Invasive Alien Species in Arctic Waters

This project is part of a joint effort between PAME and CAFF to implement actions related to the Arctic Invasive Alien Species Strategy and Action Plan.

With warming climate and increasing ship traffic there has been a growing interest and concern regarding the potential for introduction of Non-Indigenous Species (NIS) and Invasive Alien Species (IAS) to and into Arctic waters. For Arctic marine species the report assessed that ships are the most common source for the introduction of Invasive Alien Species (IAS) and Non-Indigenous Species (NIS) in Arctic marine systems, through organism entrainment in ballast water and biofouling of outer surfaces.

Based on a comprehensive review of available information in over 60 databases and 100 primary publications this report presents a list of species /taxa recognised as NIS and IAS. The report present details on individual species/taxa detections in 18 different Arctic Large Marine Ecosystems (Arctic LMEs). The list includes higher total number than in other previous studies in the Arctic waters while numbers of species/taxa recorded in the current report are similar to those found in The European Marine Observation and Data Network list.

The assessment in the report indicates that ship traffic to and into the Arctic waters has had a significant increase in the period between the years 2013 to 2024. The number of unique ships entering the Arctic area has increase by around 37%. This corresponds to approximately 500 ships, in the period from 2013 to 2023. In same period the distance sailed by ships in the Arctic Polar Code Area, has increased from 6.1 million to 12.7 million nautical miles.

Risk assessments are useful tools for developing watch lists to support monitoring and management efforts and develop watch lists of potential non-indigenous species and invasive alien species. This report employs a horizon scanning of the approach used to predict species of concern to the Arctic to date. A relatively limited number of risk assessments have been done for NIS and IAS for the Arctic waters. This report highlights that the most common approach used in risk assessments in the Arctic, has been to predict species of concern with a focus on species known to be in potential source regions and/or pathways. However, experimental information on these species´ survival and reproductive thresholds is frequently lacking, especially with respect to lower thresholds at near zero and sub-zero temperatures common to Arctic waters. In addition, species distribution models only indicate the possibility of a species to establish given the current or predicted future environmental conditions and rarely consider pathways and vectors.

To address the issue of species introductions in ballast water, the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004 (hereafter the Ballast Water Management (BWM) Convention) and the Guidelines for the Control and Management of Ships' Biofouling to Minimize the Transfer of Invasive Aquatic Species (Biofouling Guidelines 2023) were adopted. The Convention sets discharge standards for the commercial shipping to limit the number of organisms in ballast water to minimize the introduction and spread of potentially harmful aquatic organisms and pathogens. Specifically, Regulation D-2 of the Convention states that ballast water discharged into the environment shall contain < 10 viable organisms per m3 ≥ 50 μm in minimum dimension and < 10 viable organisms per mL ≥ 10 μm and < 50 μm in minimum dimension; Regulation D-2 also specifies limits for indicator microbes.This report summarizes the BWM Convention and the guidelines in an Arctic context. As of February 2025, the BWM Convention had 97 Parties representing; out of the eight Arctic Countries, two are not Parties to the BWM Convention. Recent studies indicate that even if ships are compliant with the ballast water performance standard for indicator microbes and organisms (size class 10-50 µm), some exceed the limit for viable organism’s ≥50 µm. Therefore, it is suggested to further study the efficiency of filter mesh sizes and different filtration units associated with ballast water management systems, to improve mechanical removal of larger organisms ≥50 µm.In 2023, IMO developed non-binding Biofouling Guidelines to encourage the control and management of ships' biofouling to minimize the transfer of non-indigenous species.

Arctic marine ecosystems differ from other ocean environments and are characterized by a great variability in environmental conditions, including seasonal extremes in photoperiod, cold temperatures, river runoff and ice conditions. Factors of importance in relation to the establishment of new marine species are salinity, temperature, light condition and levels of nutrients in the waters. In line with climate change, environmental and ecological conditions in the Arctic marine areas have changed in many places. Studies have documented that in Arctic regions climate-induced changes in ocean (e.g. ocean warming) and sea ice environments (e.g. sea ice loss), combined with human activities such as shipping and aquacultute have facilitate the expansion of temperate species into the regions. Based on simulations of projected climate changes for Arctic waters will push some species out of their current ranges, whereas other species may colonize new areas.

This report is Phase 1 of a joint effort between CAFF and PAME to implement actions proposed by the Arctic Invasive Alien Species Strategy and Action Plan. A phase 2 is planned to build upon results from this report and to include aspects related to risk assessments and on develope programs for monitoring, detecting, and registering of non-indigenous species (NIS) and invasive alien species (IAS) in Arctic waters.