Monitoring Coral Reefs for Global Change - Reference Methods for Marine Pollution Studies No. 61

This technical reference manual sets out standardized methods for long-term monitoring of coral reefs to detect environmental change. It was produced following an expert meeting on a global monitoring system for coastal and near-shore phenomena related to climate change, and it adopts field protocols developed through a regional collaboration involving Southeast Asian countries and Australian marine scientists. The document explains how to select reefs and sites that are suitable for repeat surveys, and it specifies a core set of ambient environmental measurements, including temperature, salinity, light penetration, cloud cover, wind, and visibility, using practical, low-cost equipment. It then details two main survey approaches: a manta tow survey for rapid, broad-scale assessment of benthic condition and major disturbances, and a line intercept transect method for characterizing sessile benthic communities using lifeform categories along fixed-length transects at defined depths. The manual stresses observer training, standardization, and strict protocols for data entry. It also describes a relational database structure linking sample information, biological observations, and ambient data to enable consistent storage, retrieval, and analysis across monitoring sites and years.