Marine spatial planning, including the designation of important marine bird areas and potential site selection for offshore energy development, requires the quantification and description of species-specific patterns in distribution with measurable habitat features. Such relationships can aid predictive models to refine population estimates at sea and delineate important habitats outside surveyed areas. In the northern California Current System, seasonal upwelling and the Columbia River plume create oceanographic structure. This structure includes enhanced phytoplankton growth and formation of physical frontal boundaries that can aggregate prey near the surface, thereby increasing availability for top-level predators. To relate patterns of seabird abundance to physical and biological characteristics of ocean habitats, we conducted aerial seabird surveys during January and June 2011 along strip-transects spanning continental shelf and slope waters off Washington and Oregon. We installed a hyperspectral radiometer and a radiation pyrometer on board the aircraft to collect simultaneous remotely-sensed reflectance and sea surface temperature, respectively. We used along-transect gradients in three ocean habitat variables (sea surface temperature, synthetic salinity, and fluorescence line height) to 1) identify frontal features associated with, and independent of, the Columbia River plume and 2) examine relationships between these features and the distribution and abundance of common marine birds. In the past, aerial seabird surveys have relied on satellite-derived products of ocean optical properties that are coarse in scale or temporally-averaged to produce better spatial coverage. Herein, we couple the ability of aerial surveys to obtain rapid coverage of large geographic areas with high-resolution, instantaneous oceanographic information.

This product is associated with the following project:
Seabird Studies at WERC

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