With our particular study, we just haven't collected or analyzed all the data yet. Only after we've been able to finish the study will I hopefully be able to distinguish the erosion due to regular river currents versus ship wake versus wind waves.
I agree. Rivers erode naturally. I define a river as something that moves water and sediment, so it is part of the natural function of the river to move sediment. The question in this case is whether ship wake is increasing the rate of that erosion.