Rapid invasion and expansion of the invasive macroalgae Rugulopteryx okamurae in the Mediterranean and Atlantic: A 10-year review

Abstract

This review seeks to establish a baseline on the current knowledge and gaps in the scientific literature on the invasive macroalgae Rugulopteryx okamurae. Through a systematic literature analysis we summarize the insights regarding distribution and potential impacts as non-indigenous species associated with its expansion from the Strait of Gibraltar since first detected by 2015. After 10 years, this invasive alien macroalgae has broadly expanded across the Mediterranean Sea (France, Spain, Morocco and Italy) and the Atlantic coasts (Morocco, Spain, Portugal, Madeira, Azores and Canary Islands). The developed research mainly shows early new detections of R. okamurae, the negative effects including both economic and ecological impacts on native biota, monitoring efforts, as well as potential applications of the biomass generated. Most of the research is mainly focused on the Strait of Gibraltar adjacent waters, making other vulnerable regions impacted unknown. These findings demonstrate R. okamurae highly invasive behavior, the need of more research regarding its spatial monitoring, impacts and potential uses, as well the complexity of cross-border coastal management. The potential invasion of broader areas in both Mediterranean and Atlantic coasts from the European and African continent requires international efforts to monitor and mitigate its ecological and economic impact, developing both scientific applications stretching efforts with specialized private companies and adapting public policies. The gaps identified in the current knowledge of R. okamurae as an invasive alien species reveal as a priority the development and implementation of an international monitoring program, integrating public participation to identify early-warnings, that could be used to quantify impacts transferable to public policies and cross-border coastal management between both continents, filling the identified management gaps opening management opportunities in the industrial sector.

Keywords: Alien species; Atlantic; Ecological impacts; Economic impacts; Invasion; Mediterranean.