Article Abstract
Work described here assessed the feasibility of using variations in tissue thickness in massive Porites corals as a bioindicator for mine-related sediment stress. We examined parameters influencing coral tissue thickness, including water depth, location, season, and time period within the lunar month. Coral tissue thickness was observed to grow linearly over the lunar cycle until it dropped abruptly by about 20% after the day of the full moon. Although some relationship was observed between tissue thickness reduction and turbidity, no systematic relationship was found between turbidity zones and light levels. The aim was to develop sampling protocols that minimized the effect of natural variability and maximized the potential use of tissue thickness by mine management as a cheap, reliable, real-time indicator of coral stress response to increased turbidity on Lihir Island, Papua New Guinea. This method could prove particularly useful at remote locations or where a fast assessment of coral stress response (< 1 month) needs to be made.