OLYMPIA, Wash. — Editor's note: The above video previously aired on KING 5 talking about the Cooke Aquaculture net pen collapse.

The Washington Department of Fish and Wildlife (WDFW) has approved an application from Cooke Aquaculture to farm all-female, sterile rainbow trout/steelhead in Puget Sound. 

The five-year permit applies to Cooke's existing net pens in Puget Sound, where Cooke already has aquatic land leases with the Washington Department of Natural Resources. 

The existing pens include four pens currently in operation near Rich Passage and Skagit Bay, and may later extend to three other net pens owned by Cooke. 

This change comes following the escape of about 250,000 non-native Atlantic salmon after a Cooke-operated net pen collapsed at Cypress Island in 2017. 

After that, the Washington State Legislature passed a bill outlawing the farming of non-native species in Washington's marine waters when the current aquatic land leases end in 2022, WDFW said. 

RELATED: Cooke Aquaculture to pay $2.75 million over 2017 net-pen collapse

The law does, however, allow for the farming of native finfish, including steelhead trout. As a result, Cooke proposed in early 2019 transitioning from farming non-native Atlantic salmon to native sterile steelhead trout and applied for the permit. 

WDFW determined the disease, escape, and genetic risks of farming sterile steelhead were "similar to or perhaps lower" than the risks related to farming the Atlantic salmon. 

WDFW is requiring Cooke to follow a series of procedures to ensure this permit does not compromise native fish populations. For instance, Cooke must farm only all-female triploid steelhead trout from embryos originating from Troutlodge in Bonney Lake. 

Other requirements range from escape prevention, response, disease reporting, and biosecurity. To learn more about the permit and its requirements, head to the WDFW website.

RELATED: Gov. Inslee signs bill phasing out Atlantic salmon farming