The first known collections of marine algae from Santa Rosa Reef, a submerged seamount located 46 km south-south-west of Guam in the Mariana Islands, occurred at 10.0 to 13.7 m depths in 2003 and 2005. Dasycladus vermicularis, a green alga known predominantly from the Caribbean but also reported from the Philippines in 1976 and the Ryukyus in 1995, and Cutleria irregularis, a brown alga first described from the Hawaiian Islands in 2003, represent the first record of D. vermicularis in the Polynesia–Micronesia region, and the first record of C. irregularis in Micronesia. In total, 8 of the 32 algal species collected at Santa Rosa Reef represent new records for the Mariana Islands.
