Diversity, Abundance, and Distribution of Macroalgae in Coastal Ecotourism Areas — A Case Study at Baluran National Park, Situbondo, Indonesia

Indonesia is a mega biodiversity country with abundant macroalgae. The macroalgae are distributed along the coast and function to maintain the balance of the coastal marine ecosystem, including in Bama Beach, Baluran National Park, Situbondo, Indonesia. This study was to determine the abundance, distribution, and diversity of macroalgae in Bama Beach Baluran National Park, East Java, between April 2019 and June 2019. The research was conducted with a purposive sampling method at two stations, each consisting of five substations using transect blocks. Five species of macroalgae from the Phaeophyceae class (Padina australis, Sargassum aquifolium, Polycladia myrica, Eucheuma edule, and Dictyota pinnatifida), a Rhodophyta (Jania pumila), and Chlorophyta (Halimeda macroloba) were found in the study site. Padina australis was a species that had the highest abundance and dominated the observation station. Nonetheless, according to the Shannon-Weaver Index in the study area, overall macroalgae diversity was classified as a low category with a value of 0.35. The high availability of nutrients influences these conditions in ecosystems with the domination of Padina australis, followed by Sargassum aquifolium at Station I and II.