Effectiveness of two western Iberian Peninsula marine protected areas in reducing the risk of macroalgae invasion

•Marine protected areas in Spain and Portugal did not avoid macroalgal invasion.•Only two out of six invasive macroalgae species were significantly abundant.•Species-specific correlations were found with cover of native canopy-formers.•Wave exposure did not affect the abundance of invasive macroalgae.•MPAs require stricter management plans to foster native macroalgal assemblages.