Thank you. The article notes that other pressures such as overfishing also contribute to the decline of fish populations, and that fish ladders on the Columbia river are successful.

No doubt there are some ineffective fish ladders out there, and no doubt dams have a negative impact on fish populations. Could better designed fish ladders and compensation channels mitigate the effect of the dam? I think so.

Fish stocks across all species are collapsing due to overfishing.