Watershed-protection advocates told Alaska lawmakers that the three transboundary rivers crossing from Canada into Southeast need more protection from the risks created by mining operations in British Columbia, including more data on water quality.

Tracking and ensuring the health of the waterways and their salmon runs, including the Stikine River, requires more monitoring over a wider area for more years, research scientist Chris Sergeant testified at the House Fisheries Committee on April 27.

“The good news … is they’re still thriving watersheds,” he said, but Sergeant cautioned t...