ANALYSIS OF PHYTOPLANKTON ABUNDANCE AS A POTENTIAL NATURAL FOOD SOURCE FOR CULTURED PINCTADA MAXIMA IN PEGAMETAN BAY, SUMBERKIMA

Abstract

Phytoplankton are an essential component of aquatic ecosystems, serving as both primary producers and a natural food source for the pearl oyster (Pinctada maxima). Pegametan Bay, Sumberkima, is an aquaculture area utilized for pearl oyster cultivation; thus, information regarding phytoplankton abundance and composition is necessary to determine the potential availability of natural food in these waters. This study aims to identify and analyze phytoplankton abundance as a natural food source at the pearl oyster cultivation site in Pegametan Bay, Sumberkima. An explorative-descriptive method was employed, utilizing purposive sampling at four stations representing different water characteristics. Sampling was conducted over three weeks at a depth of 5 m, followed by microscopic identification of the phytoplankton. The analysis included abundance, composition, diversity, evenness, and dominance indices, alongside the measurement of physico-chemical water parameters. The results showed that phytoplankton abundance ranged from 134.71 to 272.34 ind/L, with the highest abundance recorded at Station 3 (272.34 ind/L). The identified phytoplankton consisted of 56 species across six classes, with Bacillariophyceae being the dominant group (43 species). The diversity and evenness indices were classified as high, whereas the dominance index was low. This composition indicates that Pegametan Bay harbors a diverse phytoplankton community, demonstrating a strong potential to provide a natural food source for pearl oysters.