KEANEKARAGAMAN MAKROALGA DI PERAIRAN PANTAI GEGER, BALI

Geger Beach is one of the tourist attractions in Bali, where tourism activities affect the quality of Geger Beach waters. Macroalgae have ecological roles for marine ecosystems such as: as primary producers, as food sources for other biota, as shelters, as nurturing habitats, and as carbon sinks. This study aims to determine the type of macroalgae, percentage of species closure, diversity index, important value index and water quality parameters in Geger Beach. This research was carried out at 3 stations with each station having different characteristics, sampling was carried out at all three stations using quadrant transects measuring 1×1m. The observations were made at the Faculty of Marine and Fisheries, using the book "The Living Marine Resources of The Western Central Pacific Volume 1. Seawed, corals, bivalves and gastropods" Carpenter (1998) and the book "A Begginers Guide for Seaweeds identification" Kalasariya and Patel (2019). The results showed that in the waters of Geger Beach found as many as 23 species of macroalgae. The highest percentage of type closure is found in Ulva lactuca at 29%. The value of the macroalgae diversity index in Geger Beach is classified as medium category with values between 1.51-1.77. The importance index at all three stations ranged from 0-148% with the highest values in the Hypnea valentiae type.