The activist environmental organization has long been an opponent of the Alaska pollock's fishery designation by the Marine Stewardship Council as sustainable and well-managed, arguing the fleet kills too many Steller sea lions.
As part of the protest, activists are expected to dress up as "Steller sea lions" to scour Seattle for pollock.
The protest is expected to begin at Gas Works Park shortly after noon on Saturday, Greenpeace told IntraFish.
