Alien Species

Alien species are species living outside their native distributional ranges, having arrived as a result of human activities. Globally, alien species are considered the third most important threat to biodiversity after habitat loss and fishery. Alien species have the potential to impact the environment and economy, for instance by disrupting the food web or by carrying diseases or parasites.

Little is known about which alien species have reached the Arctic area, let alone established there, or what impact they may have. It is therefore necessary to have access to up-to-date information about the presence of alien species in the Arctic region. In this challenge information was gathered and presented on the introduction and distribution of alien species in the Arctic Ocean and on their (potential) impact on the ecosystem and economy.

Objective of the challenge
The objective of this challenge was to provide a table and digital map of alien species in the Arctic sea basin. The information includes:

• species name
• family (fish, algae, mammals, sponges etc)
• year of introduction
• reason for introduction (climate change, ballast water discharge etc)
• geographical area
• impact on ecosystem
• impact on economy

Indicators are used to assess (potential) impacts of alien species on ecosystem and economy.



Main results
There is no comprehensive and Arctic-specific database for alien species available. Therefore information on aliens in the Arctic Ocean was compiled from various database sources and scientific literature into a new database focused specifically on Arctic alien species. This is presented in Table 1, containing 101 established and potential alien species in the Arctic. Further detailed information is provided for each of the species separately, including species-specific taxonomy, geography, introduced range, year of introduction, vector or reason for introduction and (potential) environmental and/or economic impacts.

The available information on the identified alien species considered established in the Arctic region (from GBIF data) suggests that the majority were introduced via shipping (hull fouling or ballast water), and some via fisheries or aquaculture activities. While these activities may increase the speed of local dispersal and range extension, the temperature range of most of these species suggest that they may also be able to naturally disperse in the Arctic. As many of the established species were fouling species, habitats with hard substrates are likely to be the most sensitive to potential colonisation, while sheltered bays and inlet areas may also be sensitive to colonisation by planktonic species. While many species may have negligible effects, those that are ecological engineers or cause cascading effects in the food web may disrupt the functioning of the ecological system. Species that interfere with fisheries or aquaculture may also have an economic impact in the area. For more information, see below ‘Established Alien Species in the Arctic’.

Lessons learned
The research done for the Alien Species Challenge highlighted several gaps in knowledge that limit the comprehensiveness of the information available. These knowledge gaps consequently limit our ability to detect and predict the presence and (potential) impact of alien species in the Arctic.

In general:

• There was no existing clear and complete overview of alien species specifically in the Arctic Ocean.
• The availability of data on the presence of alien species in the Arctic and the distribution of these species in the Arctic was scarce.
• The border defining the Arctic region is unclear, this made searching for Arctic-specific information difficult.
• The status of a species as ‘alien’ or ‘native’ is not always clear due to the lack of regular monitoring in the Arctic area.
• Databases that deal with alien species do not include the Arctic region, whereas databases that concern the Arctic region, do not, or only partly, cover the species identified to be alien
• In total 101 marine alien species in the Arctic were identified from the literature. The information available relied on sporadic scientific studies that were limited in time and space (giving no indication of change), and is therefore potentially incomplete and quickly out of date. Continued and systematic research is necessary to maintain an up-to-date and relevant list of alien species.  
• Observations of Arctic alien species are often based on presence in ballast water (in Canada and Svalbard), not on actual settlement and establishment in the marine environment.
• Biological and environmental data is often lacking for the identified Arctic alien species
• Reliable and unbiased reports on (potential) impacts of alien species in the Arctic are scarce.
• The effect of climate change on the ability for certain species to expand their range to include the Arctic is currently unclear.

In particular:

• Some source websites were only available in Norwegian or French (although it is unclear if they provided the appropriate data). Where English versions were available, they were often less complete than the original version.
• Some source websites were not user-friendly. Data was often difficult to access and required various search methods for different websites.
• No databases were found in Russian or Chinese. Whether these do not exist (publically) or were not found due to the language is unclear.
• We could not access data that was not publically available, and it is unclear if these data contain more appropriate information.

Recommendations

• Develop standard monitoring for detecting alien species in the Arctic, particularly in areas where human activity is regular or increasing such as on Svalbard. This can consist of annual monitoring by sampling sessile, plankton, and soft sediment in main commercial ports. Analysis can consists of traditional taxonomic identification and/or more innovative methods such as DNA barcoding.
• Improve current databases by adding Arctic areas to alien species databases and adding alien species information to Arctic databases.
• Improve communication and coordination with other national monitoring in Russia and Canada to further obtain comprehensive, standardised and reliable Arctic-specific information. In the near future a new version of the Norwegian black list for alien species is expected that may provide further input on the presence, distribution and potential impacts of alien species in the Arctic.
• Stimulate research, including experimental studies, to fill the knowledge gap about which, to what extent, and in what circumstances alien species may have an impact on the Arctic ecosystem and economy.
• Stimulate research to make informed projections about the effects climate change may have on the introduction of alien species to the Arctic.

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References (most relevant)

• http://citeseerx.ist.psu.edu
• https://eol.org/
• http://invasions.si.edu
• http://onlinelibrary.wiley.com
• http://species-identification.org
• http://www.anstaskforce.gov/EcoSurveys
• http://www.cabi.org
• https://www.cabi.org/isc/
• http://www.gbif.org
• http://www.iucngisd.org
• http://www.nrcresearchpress.com
• http://www.pwsrcac.org
• http://www.sms.si.edu
• https://rafhladan.is
• https://www.eoas.ubc.ca/research
• https://www.nobanis.org
• https://www.researchgate.net
• https://www.nobanis.org/fact-sheets
• Norton, B.G. (2014). The Preservation of Species. Princeton University Press.
• Ware, C., Berge, J., Jelmert, A., Olsen, S. M., Pellissier, L., Wisz, M., Kriticos, D., Semenov, G., Kwasniewski, S. and Alsos, I. G. (2016), Biological introduction risks from shipping in a warming Arctic. J Appl Ecol, 53: 340–349. doi:10.1111/1365-2664.12566
• https://www.vliz.be/en/vliz-publications

 

 Table 1. Overview of marine alien species in the Arctic

 

The following publication related to this challenge has been published:

ALIEN SPECIES IN THE ARCTIC OCEAN - BACHELOR THESIS