ANALYSIS OF CHLOROPHYLL-A DISTRIBUTION AS AN INITIAL INDICATOR OF POTENTIAL FISHING ZONES IN WAKATOBI WATERS AND SURROUNDING AREAS

Wakatobi waters in Fisheries Management Area (WPP) 714 are an important habitat for large pelagic fish, such as tuna, skipjack, and mackerel. However, fishing activities still rely on fishermen's experience, resulting in suboptimal utilization of fishery resources. Remote sensing technology provides oceanographic information, including chlorophyll-a concentration, as an initial indicator for developing maps of potential fishing zones. This study aims to analyze the spatial and temporal distribution of chlorophyll-a concentration and its spatial clustering patterns in Wakatobi waters and its surroundings. The data used are derived from Aqua MODIS satellite imagery for the period 2022–2024. Spatial analysis was conducted using the Getis-Ord Gi* method, while temporal analysis examined variations in chlorophyll-a concentration by month and season. The results showed that chlorophyll-a concentration ranged from 0.129853–0.338896 mg/m³. Chlorophyll-a hotspots were consistently identified in the southwest part of Wakatobi Island, which is dominated by shallow waters and coral reef ecosystems. Most of the open waters fall into the "not significant" category, indicating the absence of significant spatial clustering of chlorophyll-a as hotspots or coldspots, but this does not necessarily mean that concentrations are low or absent. Temporally, the highest concentrations occur in July–September, with a peak in August, while the lowest concentrations occur in April and November. The distribution pattern of chlorophyll-a is thought to be influenced by seasonal dynamics, monsoon winds, and the Indonesian Throughflow (Arlindo). The results provide basic information on the spatial and temporal characteristics of chlorophyll-a to support potential fishing-zone identification in Wakatobi waters.