Brown algae invasions and bloom events need routine monitoring for effective adaptation

Brown algae blooms and invasions have affected 29% of the Earth's coast, yet there is sparse evidence of the impacts and adaptations of these events. Through a systematic review of empirical literature on these blooms and invasions, we explore the prevalence of conventional analyses of environmental, economic, and social impacts, as well as opportunities for adaptation and valorisation. The study reveals crucial inconsistencies in the current evidence base on algae impacts: fragmented metrics for quantifying blooms and their effects; inconsistent application and testing of prevention measures (e.g. forecasting, early warning systems); reliance on removal as a management approach with limited evidence of associated costs; and scant evidence of the effectiveness of impact mitigation or adaptation strategies. With a focus on economic and societal dimensions of algae events, we introduce emerging opportunities within the blue economy for bloom utilization. The findings highlight the crucial need for harmonized monitoring protocols, robust cost-benefit analysis of management and adaptation options, and evidence of pathways to valorisation of algae biomass.