Assessing long-term coral reef degradation in Indonesia’s Tiworo strait marine conservation area using remote sensing and rapid appraisal for fisheries approaches

Abstract

In Indonesia, the coral reef ecosystem in the Tiworo Strait Conservation Area (TSCA) faces various threats of natural and anthropogenic stressors that can damage the coral reef ecosystem's role and services. We analyzed changes in coral reef habitat at TSCA over the 25 years from 1994 to 2019 using multi-temporal and multi-sensor satellite imagery data combined with in-situ measurement data and social surveys. Our results show a decrease in live coral cover from 78.30 ha in 1994 to 8.01 ha in 2019, with a 2.81 ha/year degradation rate. Our analysis of 37 threat attributes shows that the TSCA coral reef ecosystem faces a "high threat" to very high threat levels. Threat scores for coral reefs assessed as facing severe conditions according to threat indices included contributions from the ecological dimension (16.87 = very high threat), economic dimension (31.00 = high threat), social dimension (34.83 = high threat), technological dimension (41.10 = high threat), and law and institutional dimension (26.83 = high threat). Coral reefs will undoubtedly go extinct if local threats continue without preventative measures.Therefore, the sustainability of coral reefs in the TSCA-one of the most important marine conservation sites in the Coral Triangle Marine Eco-region should be the primary priority for all stakeholders. Appropriate policies and supervision in the field must be carried out rigorously and measurably, implementing the analyzed set of strategies.