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New study looks at trends in detecting non-indigenous marine species

New study looks at trends in detecting non-indigenous marine species

An aquatic non-indigenous species is detected on average every 8.4 days. A new study from ICES groups on Introductions and Transfers of Marine Organisms and Ballast and Other Ship Vectors looks at trends in detection since 1965.

Wooden pallets, marine litter, ship hulls, fishing gear. Ballast water and airplanes. Contaminants on animals, plants, or bait. Intentional release or lucky escape. There are many pathways for organisms to hitchhike their way to a new environment and establish as a non-indigenous species.

The introduction of aquatic non-indigenous species (ANS) has become a major driver for global changes in species biogeography. It is an issue addressed by both ICES Working Group on Introduction and Transfers of Marine Organisms (WGITMO) and ICES-IOC-IMO Working Group on Ballast and Other Ship Vectors (WGBOSV). Together, these groups collaborate on the introduction and transfer of biofouling organisms through ship vectors, as well as on climate change impacts on the establishment and spread of ship-mediated nonindigenous species, particularly as they relate to the Arctic. The groups have now jointly produced an impressive paper examining spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management​.

The authors chose to cover a 50-year period (1965-2015) “with the assumption that there has been increasing awareness and more comprehensive reporting since 1965, with time‐lags presumably being smaller compared to reports prior to 1965”.

More than 2200 records were assembled for this time period across 49 global aquatic ecosystems – approximately one new detection every 8.4 days. This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global-scale comparisons and sustain core measures over longer timescales.

Lisa Drake, Chair of WGBOSV states that, “This ambitious analysis is quite timely. It can be used to inform management decisions, since limited resources must be allocated to reduce the transport, release, and spread of ANS, which occur via multiple pathways. Additionally, this 50-year perspective provides an important lens through which the effects of regulatory measures can be assessed over time”.

WGITMO and WGBOSV are composed of scientists with extensive knowledge of ship-mediated biological invasions who strive to advance the scientific understanding needed to guide management and policy decisions. The groups enjoy a very close working relationship and for nearly 20 years, have held joint meetings to discuss new research findings, share ideas, and develop future collaborations.

Sarah Bailey, lead author and Chair of ICES Human Activities, Pressures and Impacts Steering Group (HAPISG) adds, “This paper was a direct result of the working groups’ shared terms of reference and wouldn’t have come together without networking and communications during annual working group meetings”.

Species on the move

The slipper limpet, Crepidula fornicata, is one example of a species unintentionally introduced. Originally, the growing popularity in oyster consumption towards the end of the nineteenth century in Britain, led to the import of American oysters from the east coast of the USA. C. fornicata were present on these oysters that were stored in barrels in bays.

Thousands of vessels and floating landing stages used for the Normandy D-Day landings in the Second World War played a second part in the further distribution of C. fornicata, along with allied boats that had come from the USA or northern Europe.

  1. fornicatanow stretches over 24 degrees of latitude, distributed on all European seasides and the English Channel.​

Read the full paper Trends in the detection of aquatic non-indigenous species across global marine, estuarine and freshwater ecosystems: a 50-year perspective​ in Diversity and Distributions.

Source: ICES