Last week I went to an interesting talk What are the effects of dredging on the Great Barrier Reef?
by Laurence McCook, at the Global Change Institute at UQ.
I went because I knew Laurence in my undergraduate days at ANU. In first year we had all the same lectures, tutorials, and labs. (I guess groups were assigned based on the alphabet.) We became friends and he introduced me to many beautiful places for bushwalking [backpacking] and cross country skiing near Canberra.
There is a piece on the Conversation that gives a brief summary of the issues associated with the report from the expert panel that Laurence and Britta Schaffelke co-chaired. Basically, it involved a "cat herding" exercise with 17 experts from industry, government, and universities. I am always impressed by people who manage such enterprises and can produce concrete useful outcomes. I think it requires considerable patience, political skills, and leadership.
A helpful figure is below.
Aside: it would be interesting to try and do an exercise like this for topics such as cuprate superconductors, topological quantum computing, water, glasses, quantum molecular biophysics......
So what effect does dredging have?
Specifically, which of the effects is most likely to do the greatest environmental damage?
It seems that the ongoing turbidity [cloudy water] and sedimentation associated with sediment dynamics could be the biggest problem. But, this is also one of the most poorly understood processes.
The figure below summarises some of the complex processes involved. Modelling this presents a major challenge (and some interesting science).
It is interesting that of "10 scientific ideas that scientists wish you would stop mis-using" the first is Proof.