Trends in the detection of aquatic non‐indigenous species across global marine, estuarine and freshwater ecosystems: A 50‐year perspective

Type Article
Date 2020-12
Language English
Author(s) Bailey Sarah A.1, Brown Lyndsay2, Campbell Marnie L.3, Canning‐clode João4, 5, Carlton James T.6, Castro Nuno4, Chainho Paula7, Chan Farrah T.1, Creed Joel C.8, Curd AmeliaORCID9, Darling John10, Fofonoff Paul5, Galil Bella S.11, Hewitt Chad L.12, Inglis Graeme J.13, Keith Inti14, Mandrak Nicholas E.15, Marchini Agnese16, McKenzie Cynthia H.17, Occhipinti‐ambrogi Anna16, Ojaveer Henn18, 19, Pires‐teixeira Larissa M.7, 20, Robinson Tamara B.21, Ruiz Gregory M.10, Seaward Kimberley13, Schwindt Evangelina22, Son Mikhail O.23, Therriault Thomas W.24, Zhan Aibin25, Hussey Nigel
Affiliation(s) 1 : Great Lakes Laboratory for Fisheries and Aquatic Sciences Burlington ON, Canada
2 : Marine Lab Marine Scotland Sci Aberdeen, UK
3 : School of Life and Environmental Science Deakin University Geelong Vic., Australia
4 : MARE – Marine and Environmental Sciences Centre Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI) Madeira Island ,Portugal
5 : Smithsonian Environm Res Ctr Edgewater MD, USA
6 : Maritime Studies Program Williams College – Mystic Seaport Mystic CT ,USA
7 : Faculdade de Ciências MARE – Marine and Environmental Sciences Centre Universidade de Lisboa Lisbon, Portugal
8 : Departamento de Ecologia Universidade do Estado do Rio de Janeiro Rio de Janeiro, Brazil
9 : Ifremer DYNECO, Centre Ifremer de Bretagne Plouzané ,France
10 : Center for Environmental Measurement & Modeling United States Environmental Protection Agency Research Triangle Park NC, USA
11 : The Steinhardt Museum of Natural History Tel Aviv University Tel Aviv, Israel
12 : Harry Butler Institute Murdoch University Murdoch, 6150 Western Australia ,Australia
13 : National Institute of Water & Atmospheric Research Ltd. Christchurch, New Zealand
14 : Charles Darwin Research Station, Charles Darwin Foundation Santa Cruz, Galapagos ,Ecuador
15 : University of Toronto Scarborough Toronto ON ,Canada
16 : Department of Earth & Environmental Sciences University of Pavia Pavia, Italy
17 : Northwest Atlantic Fisheries Centre Fisheries Oceans Canada St John's NL ,Canada
18 : Pärnu College University of Tartu Pärnu ,Estonia
19 : National Institute of Aquatic Resources Technical University of Denmark Kgs. Lyngby, Denmark
20 : Programa de Pós-Graduação em Ecologia e Evolução, Universidade do Estado do Rio de Janeiro Rio de Janeiro, Brazil
21 : Department of Botany and Zoology, Centre for Invasion Biology Stellenbosch University Stellenboch ,South Africa
22 : Instituto de Biología de Organismos Marinos (IBIOMAR‐CONICET) Puerto Madryn ,Argentina
23 : Institute of Marine Biology NAS of Ukraine Odessa ,Ukraine
24 : Pacific Biological Station Fisheries & Oceans Canada Nanaimo BC ,Canada
25 : Research Center for Eco‐Environmental Sciences Chinese Academy of Sciences Beijing ,China
Source Diversity And Distributions (1366-9516) (Wiley), 2020-12 , Vol. 26 , N. 12 , P. 1780-1797
DOI 10.1111/ddi.13167
WOS© Times Cited 103
Keyword(s) aquatic non-indigenous species, biological invasions, detection rate, inventory, long-term dataset, population status, richness, spatial patterns, temporal trends, transport pathways


The introduction of aquatic non‐indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management.




We assembled an extensive dataset of first records of detection of ANS (1965–2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways.


An annual mean of 43 (±16 SD) primary detections of ANS occurred—one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965–1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005–2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships’ ballast water or biofouling, although direct evidence is typically absent.

Main conclusions

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. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. 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 time‐scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management.

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Bailey Sarah A., Brown Lyndsay, Campbell Marnie L., Canning‐clode João, Carlton James T., Castro Nuno, Chainho Paula, Chan Farrah T., Creed Joel C., Curd Amelia, Darling John, Fofonoff Paul, Galil Bella S., Hewitt Chad L., Inglis Graeme J., Keith Inti, Mandrak Nicholas E., Marchini Agnese, McKenzie Cynthia H., Occhipinti‐ambrogi Anna, Ojaveer Henn, Pires‐teixeira Larissa M., Robinson Tamara B., Ruiz Gregory M., Seaward Kimberley, Schwindt Evangelina, Son Mikhail O., Therriault Thomas W., Zhan Aibin, Hussey Nigel (2020). Trends in the detection of aquatic non‐indigenous species across global marine, estuarine and freshwater ecosystems: A 50‐year perspective. Diversity And Distributions, 26(12), 1780-1797. Publisher's official version : , Open Access version :