Assessing Anthropogenic Impacts on Coral Reefs Using Local and Expert Knowledge in the Semporna Priority Conservation Area, Sabah, Malaysia

The Semporna Priority Conservation Area (PCA), located on the southeast coast of Sabah, Malaysia, spans 7680 km² within the Sulawesi Sea and is part of the Coral Triangle, known for its rich marine biodiversity. Despite its ecological significance, the area faces multiple anthropogenic threats. The study aimed to (1) evaluate reef health by assessing live coral cover, indicator fish and invertebrate density in six locations in Semporna; (2) examine the survey team's threat rankings with the vulnerability factors perceived by experts; and (3) compare vulnerability scores for 10 identified threats. Underwater surveys were conducted using the Reef Check methodology, supplemented by in situ observations from SCUBA divers and boat attendants in May–June 2017. Marine biologists or scientists familiar with Semporna assessed coral reef vulnerability factors based on scales, frequency, functional impact, resistance, recovery time and certainty towards different threats. The main threats identified include fish bombing, marine debris, commercial fishing and artisanal fishing. Results indicate reef degradation, particularly from destructive fishing practices, and highlight differences between local observations made by the field team and expert assessments gathered through interview surveys. Tourism activities were significant in the Centre to Southwest and Northeast to Southwest regions, necessitating site-based management. This integrated approach provides a comprehensive understanding of threats in the Semporna PCA and underscores the importance of combining empirical data with local insights to guide management prioritisation and develop effective conservation strategies, such as establishing new marine protected areas.