Tracking macroalgae introductions in North Atlantic oceanic islands

The Azores archipelago was selected as a case study since there are few studies on macroalgae introduction in oceanic islands. While at a global scale, around 3 % of macroalgae are considered non-indigenous; in the remote oceanic islands of the Azores, over 6 % of the marine algal flora is non-indigenous. The taxa distribution pattern of non-indigenous species in the Azores is significantly different from the distribution pattern in the globe. The most representative group was Rhodophyta species, being 84 % of the total non-indigenous macroalgae, mainly introduced via maritime traffic. This study highlights the vulnerability of remote islands to the introduction of macroalgae and the need to develop further studies on other archipelagos to understand whether the observed vulnerability is generally characteristic of oceanic islands. The development of local monitoring and mitigation programs and the necessity of regulatory and preventive measures for the maritime traffic vector are strongly suggested.