Some aspects of lagoon sedimentation and circulation at One Tree Reef, Southern Great Barrier Reef

Observations of water movement at One Tree Reef under modal wind, wave, and tide conditions show that the lagoon currents are insufficient to entrain lagoon sediments and cannot account for the windward to leeward decrease in sediment size across the lagoon. Bioturbation may suspend bottom material long enough for it to be transported a short distance by the ambient current, depending on the grain size and current velocity. In addition, low-frequency, high-energy events largely produce the same southeast to northwest movement of water observed under modal energy conditions and would be responsible for transporting and sorting large volumes of sediment over a short period. Patch reefs locally supply significant amounts of sediment directly to the lagoon, resulting in a local increase in sediment size and a characteristic build-up of material and extension of patch reefs to leeward. These observations are directly applicable to other reefs with well-developed lagoons in the southern Great Barrier Reef and may also apply to similar reefs in other parts of the Great Barrier Reef.

在典型风、浪和潮汐条件下对一树礁（One Tree Reef）水体运动的观测表明，潟湖水流不足以卷携潟湖沉积物，也无法解释整个潟湖从迎风侧到背风侧沉积物粒径的减小。生物扰动（Bioturbation）可能使底部物质悬浮足够长的时间，使其能被环境水流短距离搬运，具体取决于颗粒大小和水流速度。此外，低频高能事件产生的水流运动与典型能量条件下观测到的东南向西北运动基本一致，且会在短时间内负责搬运和分选大量沉积物。斑块礁在局部直接向潟湖提供大量沉积物，导致局部沉积物粒径增大，以及典型的物质堆积和斑块礁向背风侧延伸。这些观测结果直接适用于大堡礁南部其他具有发育良好潟湖的礁体，也可能适用于大堡礁其他区域的类似礁体。