Evaluation of antimicrobial activity of the extracts was performed by agar diffusion test against clinically relevant strains in solid agar plates: Gram-positive Bacillus subtilis MB964 and methicillin-resistant Staphylococcus aureus MB5393, Gram-negative Acinetobacter baumannii MB5973, and Candida albicans MY1055, all from Fundación Medina’s collection. The seeds and assay plates were prepared as described previously [41]. Marine crude extracts were dispensed both in wells (10 μL) onto agar plates (12 cm × 8 cm) or as 10 μL and 20 μL drops on the surface of Nunc agar plates (24 cm × 24 cm). Inhibition zones were measured in mm after 24 h incubation at 37 °C.