The benthic marine algae of the Maldives: historical insights into their diversity and distribution

In tropical ecosystems worldwide, benthic marine algae are important primary producers and habitat providers for many juvenile fish and invertebrate species. Calcified species are known to provide structural support to their respective communities, thus enhancing the overall system’s productivity. In the Republic of the Maldives, algae are an important yet currently poorly studied biological resource. We reviewed the literature around algal diversity and distribution across Maldivian atolls and compiled an extensive and updated taxonomic list. The list contains 353 species, of which 31 are Cyanobacteria, 26 Phaeophyceae, 109 Chlorophyta, and 187 Rhodophyta. Algal collections have been reported from 12 out of 20 atolls, and these mostly occurred during 20th century expeditions. The taxonomic status of 110 species has changed since first reported. While several species have been documented from the country, identifications have thus far almost solely relied on morphological assessments. Many of the reported algal groups require molecular confirmation. This suggests that benthic algal diversity from the Maldives is likely an underestimate. Since anthropogenic activities can significantly alter algal community dynamics, a baseline understanding of algal diversity is necessary to determine how such shifts affect the ecosystem as a whole, thus underpinning future management and conservation efforts.