Status and Trends of the Salish Sea\u27s Marine Birds

Seabirds are often used in ecosystem monitoring programs not only because they are ubiquitous, conspicuous and charismatic but also because they are relatively well studied, time-series exist for many species, and because some species are tightly linked to their habitats, prey resources, or climatic/oceanographic conditions. The marine bird community of the Salish Sea is composed of over 70 species that are relatively abundant and highly dependent upon marine resources but their relative abundance changes dramatically throughout the year. During the summer months, the Salish sea seabird community is dominated by locally breeding birds including gulls, alcids, and cormorants. However, during the period between late-fall and early spring there is nearly a four-fold increase in abundance and the community becomes much more diverse with the influx of ducks, mergansers, grebes, and others. To help set the stage for a broader discussion about the mechanisms responsible for seabird population trends, we present a broad overview of seabird population trend patterns for this complex community using provincial, state and non-governmental monitoring data sets covering the past 5-20 years depending on the effort. We will present abundance trends by residency (local breeder, migrant, over-wintering), diet, and habitat use (nearshore, pelagic). Trends are complex with a few over-wintering species like scoters and loons exhibiting declines and local breeders monitored during the nesting season exhibiting no significant trend or increases. These trends appear to vary geographically with some variation among monitoring programs