Cooke Aquaculture wants to use its fish farming pens off the southern coast of Bainbridge Island to raise rainbow trout, officials with the Washington Department of Ecology said Tuesday, and has submitted applications to the state requesting modifications to its existing water quality permits for its Bainbridge operation and three other net pens in Puget Sound.

Ecology officials said it will accept public comments on the proposal online through May 22.

Cooke Aquaculture said it will use its fish pens to raise all-female, sterile rainbow trout, also known as steelhead, which are native to Washington instead of non-native Atlantic salmon.

Ecology officials that the company will need to navigate a multi-agency, multi-step permitting process to change the type of species allowed in its existing permits.

The Washington Department of Fish & Wildlife — regulates ecological impacts of marine aquaculture to prevent disease and harmful effects to wild stocks — approved Cooke’s request to farm native steelhead in January.

Ecology regulates marine net pen aquaculture to protect water quality through the National Pollutant Discharge Elimination System.

State officials said the public comment period is the first step in Ecology’s process.

Following the comment period, agency officials will review the public feedback and determine if and how to modify the permits to continue protecting water quality.

If Ecology decides to modify the existing permits, the agency said, drafts will be available for public review and feedback. Those drafts will likely not be ready until summer 2020.

The change for Cooke follows a law passed in 2018 by the Legislature that bans non-native marine net pen fish farming by 2022.

Officials noted that because steelhead are native, they are not covered by the 2018 law.

A decision by Ecology to modify the current permits will not extend the permit length, which expire in 2024. The permits were originally issued to allow for two years of closure activities and monitoring after Cooke’s aquatic lands leases from the Department of Natural Resources expire in 2022.

For Cooke Aquaculture to continue with these net pens past 2022, officials said, DNR will have to approve new aquatic land leases.

Cooke’s fish pens off Bainbridge Island are located near Fort Ward.

The net pen-rearing area is 650 feet by 185 feet, and is 750 feet from the shore.

The operation produces approximately 4.5 million pounds of fish a year, according to the company’s application for its Fort Ward facility, and the fish that are farmed are fed food that ranges from 480,000 pounds in May to 340,000 pounds in July.

Dead fish are removed from the pens three times a week, and according to the company’s application, fish mortalities at the Fort Ward site total approximately 5,000 pounds a month.

Comments can be submitted at http://wq.ecology.commentinput.com/?id=BJeUR.