Five Democratic senators are asking President Obama to consider blocking a proposed mine in Alaska’s Bristol Bay, a move that could heighten pressure on the Environmental Protection Agency to veto the project. The group of senators from Washington, Oregon and California, led by Maria Cantwell (Washington), argue that their states could suffer economically if a huge gold-and-copper mine moves forward. The EPA is conducting a scientific review of how the project, underwritten by mining giants Northern Dynasty (in which Rio Tinto has a minority stake) and Anglo American, would affect the region’s aquatic life.