By comparison, the marine survival of coastal and Columbia River Chinook, coho, and steelhead does not follow the same declining trend as the Salish Sea populations. This suggests that the problem lies within the Sea itself and not the open ocean shared by all Pacific salmonids.
Historically, our collective understanding of what drives salmon and steelhead survival in saltwater has been extremely limited, and has been acknowledged by natural resource managers as a critical information gap that must be addressed in order to make real progress toward salmon recovery and sustainable fisheries.
The Salish Sea ecosystem has changed significantly over the period in which salmon populations have declined. Changes have included increasing water temperatures, increasing acidity, more harmful algae, the loss of forage fish and some marine commercial fishes, changes in marine plants, more seals and porpoises, and the list goes on…