Washington state officials are moving forward with Cooke Aquaculture's proposal to raise rainbow trout in its Atlantic salmon pens, which are otherwise set to be phased out of existence by 2022.

The Washington Department of Fish and Wildlife (WDFW) said Tuesday it plans to issue a five-year Marine Aquaculture Permit to Cooke to culture all-female triploid rainbow trout at its existing netpens in the Puget Sound, according to state documents.