1.   At the same time, salmon, the very symbol of the region, are struggling to survive because dams block their migratory routes.

2.   Dams block fish passage along the five of the eight major tributaries of the Columbia.

3.   Dams also block migrating fish and the flow of nutrients, slow and heat the water and kill fish in electric turbines.

4.   Dams block fish passage along the five of the eight major tributaries of the Columbia River.

5.   Some Columbia basin populations, ones whose passage was completely blocked by dams, have long since become extinct.

6.   The dams blocked off the roads out of the city in several places, preventing people from leaving Yakutsk.

7.   They also may consider building dams to block them, she said.

8.   The dam blocks a tributary feeding into the Red River.