ORIGINAL PAPER Identifying marine invasion hotspots using stacked species distribution models Devin A. Lyons . J. Ben Lowen . Thomas W. Therriault . David Brickman . Lanli Guo . Andrea M. Moore . M. Angelica Pen ˜a . Zeliang Wang . Claudio DiBacco Received: 9 August 2019 / Accepted: 7 August 2020 Ó Springer Nature Switzerland AG 2020 Abstract Early detection and management of aqua- tic invasive species requires identification of those areas most at risk of invasion (i.e., hotspots). Here we identify present-day and future hotspots of invasion risk for marine invertebrates and algae in nearshore habitats of the northwest Atlantic and northeast Pacific using more than 12 years of monitoring data in conjunction with other occurrence data and stacked species distribution models. The stacked species distribution models predicted the general patterns of observed invasive species richness in both study areas (Atlantic: r 2 = 0.52, Pacific: r 2 = 0.42). In the northwest Atlantic, we identified hotspots through much of Massachusetts, New Hampshire and southern Maine, and in several bays in southwestern New Brunswick and Nova Scotia. In the northeast Pacific, much of the southern Salish Sea was identified as a hotspot, as were a few areas along the outer coast of Washington and Oregon. Projecting our species dis- tribution modelling results to 2075 (climate scenario RCP 8.5), we found that existing hotspots are likely to expand slightly in the Atlantic, while in the Pacific existing hotspots are predicted to shift or expand, new hotspots are likely to appear, and areas with few invasive species attaining moderate invasive species richness. Our results suggest that climate change will have larger effects on the distributions of our focal invasive species on the Pacific coast compared to the Atlantic. Resultant hotspot maps provide an integrated perspective and guidance to managers tasked with prioritizing locations for monitoring and implement- ing policy related to marine invasive species, with projected hotspots making planning for future changes in invasion risk possible. Keywords Marine invasive species Á Species distribution models Á Climate change responses Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10530-020-02332-3) con- tains supplementary material, which is available to authorized users. D. A. Lyons (&) Á J. B. Lowen Á D. Brickman Á L. Guo Á A. M. Moore Á Z. Wang Á C. DiBacco Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS, Canada e-mail: dalyons@dal.ca D. A. Lyons Department of Zoology, University of British Columbia, Vancouver, BC, Canada T. W. Therriault Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, Canada M. A. Pen ˜a Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC, Canada 123 Biol Invasions https://doi.org/10.1007/s10530-020-02332-3