Surf Scoter (Photo by Andy Reago & Chrissy McClarren)

From Cornell Lab:

On the Pacific Coast, preliminary studies indicate that survivorship is high at major molting sites, but survivorship can be markedly lower during winter depending on location, age, and body mass. During nonbreeding periods, Surf Scoters aggregate in coastal sites where they are often exposed to a suite of human impacts. The role of these impacts on scoter population processes requires further study, but important impacts likely include: degradation and loss of nearshore feeding habitats (e.g., effects of shoreline armoring, and loss of critical habitats such as seagrass beds); developmental and reproductive consequences of elevated contaminant exposure, including both acute and chronic affects of oil exposure (scoters are one of the species most frequently caught in oil spills); changes in predator communities; disturbance by watercraft; and introductions of invasive prey items. https://birdsna.org/Species-Account/bna/species/sursco/introduction