The first comprehensive taxonomic treatment of these two groups of marine plants for the tropical and subtropical Pacific, "Marine Green and Brown Algae of the Hawaiian Islands" covers intertidal and deep subtidal habitats (to depths of 300 ft.) of the Northwestern Hawaiian Islands and the main Hawaiian Islands. Many new species and records of distribution in the Hawaiian Islands are described, with 61 species of brown algae and 105 species of green algae, which join the previously published red algae, making a total of 514 marine algae for the Hawaiian Islands.