A booming population of hatchery-raised fish could put pressure on salmon streams that are already vulnerable due to climate change.
"hypoxia"
Coastal pacific oxygen levels now plummet once a year
The hypoxia season hits Oregon, Washington and California waters in the summer and can last from a few days to a couple of months. Some years it only affects a few square miles of ocean; other years it’s thousands of square miles.
Coastal researchers, fishermen worried about more frequent low oxygen zones
Scientists in Oregon and Washington are noticing a disruptive ocean phenomenon is becoming more frequent and extreme. It involves a suffocating ribbon of low oxygen seawater over our continental shelf. The technical term is hypoxia, sometimes called “dead zones.”