QGIS-based spatial analysis of coral reef ecotourism suitability and environmental carrying capacity in Isa’u Island, Indonesia

¹ Coastal and Marine Resource Management Study Program, Faculty of Fisheries and Marine Sciences, IPB University (Bogor Agricultural University), IPB Darmaga Campus, Jl. Agatis, Bogor 16680, Indonesia.
² Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, IPB University (Bogor Agricultural University), IPB Dramaga Campus, Jl. Agatis, Bogor 16680, Indonesia.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Coral reefs provide an important ecological basis for coastal ecotourism and marine biodiversity conservation. However, the sustainability of reef-based tourism is not determined only by ecosystem condition, but also by the type and intensity of tourism activities, visitor behavior, and management practices. Coral reef condition remains an important indicator for assessing the ecological suitability of marine tourism activities such as snorkeling and diving. This study was conducted on Isa’u Island, Negeri Pasanea, which has great potential as a marine ecotourism destination, but tourism development must be balanced with ecosystem protection. The purpose of this study was to assess the suitability of coral reef areas for snorkeling and diving activities and to estimate their carrying capacity based on suitable area size, space requirement per visitor, daily available tourism time, and average activity duration. Field observations were conducted using Underwater Photo Transect and Underwater Visual Census methods. Carrying capacity was calculated by integrating the area suitable for each tourism activity with visitor space requirements and the ratio between available daily tourism time and average activity duration.Live coral cover ranged from 51.28% to 66.79%, indicating good reef condition. The tourism suitability index was calculated using weighted biophysical parameters relevant to snorkeling and diving activities, such as coral cover, water conditions, depth, current velocity, and reef-fish condition. Based on this index, snorkeling was suitable in areas 3 and 5, while diving was suitable in areas 1, 2, and 3. Across the suitable reef-tourism zones of Isa’u Island, the estimated carrying capacity was 52 visitors/day for snorkeling and 58 visitors/day for diving. These findings indicate that reef-based tourism on Isa’u Island should be managed through spatial zoning, daily visitor quotas, periodic coral reef monitoring, and guide-based supervision so that snorkeling and diving use remains within the ecological carrying capacity of the reef.