(CNN)Within hours of meeting with a mining company CEO, the new head of the US Environmental Protection Agency directed his staff to withdraw a plan to protect the watershed of Bristol Bay, Alaska, one of the most valuable wild salmon fisheries on Earth, according to interviews and government emails obtained by CNN.

The meeting between EPA Administrator Scott Pruitt and Tom Collier, CEO of Pebble Limited Partnership, took place on May 1, Collier and his staff confirmed in an interview with CNN. At 10:36 a.m. that same day, the EPA's acting general counsel, Kevin Minoli, sent an email to agency staff saying the administrator had "directed" the agency to withdraw an Obama-era proposal to protect the ecologically valuable wetland in southwest Alaska from certain mining activities.

In 2014, after three years of peer-reviewed study, the Obama administration's EPA invoked a rarely used provision of the Clean Water Act to try to protect Bristol Bay after finding that a mine "would result in complete loss of fish habitat due to elimination, dewatering, and fragmentation of streams, wetlands, and other aquatic resources" in some areas of the bay.

"All of these losses would be irreversible," the agency said.
The area is regarded as one of the world's most important salmon fisheries, producing nearly half of the world's annual sockeye salmon catch. Its ecological resources also support 4,000-year-old indigenous cultures, as well as about 14,000 full- and part-time jobs, according to the EPA's 2014 report.