Finding out when dredging starts damaging coral

Cutting-edge underwater monitoring technology has enabled researchers working on a NESP TWQ project to develop models to help decision-makers assess the risk posed to inshore corals by port dredging. The project team, led by Dr Ross Jones at the Australian Institute of Marine Science, collected a wide variety of water condition data in close proximity to a working suction-hopper dredge at Cleveland Bay near Townsville. Light is essential for corals and the researchers used a variety of methods including multi- and hyper-spectral light sensors to describe how water cloudiness (turbidity) caused by dredging and storms changes the quantity and the quality of underwater light. The data was then used to develop highly accurate simulations at the Australian Institute of Marine Science’s SeaSim aquarium facility, and the responses of several species of inshore coral and sponges examined over extended periods. The results and analyses in the project’s recent final report have provided a means of assessing whether the changes in underwater light associated with dredging could have biological effects – and hence to reactively manage the dredging activity.

 

Photo: Ross Jones