Cross-platform Ecosystem Assessment Through Characterization of Prey Habitat Suitability and Predator Occurrence off Newport, Oregon

The coastal waters off Newport, Oregon are part of a naturally dynamic ecosystem influenced by the California Current. In additional to highly variable interannual and decadal processes, recent environmental monitoring has indicated instances of persistent warm water masses in the region. One method of assessing long standing shifts in the ecology of this coastal and offshore environment is to associate physical oceanographic variables with the presence of indicator species such as marine mammals. Using cross-platform oceanographic and spatial data sources, we evaluated prey habitat suitability and marine mammal distribution across three years. The Ocean Observatories Initiative (OOI) maintains a series of coastal and offshore monitoring platforms and data systems that include cabled sensors and gliders. Since 2016, this conglomeration of resources has continuously collected information such as temperature, dissolved oxygen, pH, pCO₂, chlorophyll and nitrate from the continental shelf near Newport out to the Axial Seamount along the Juan de Fuca Ridge. Gliders travel along five east-west transect lines from a depth of 0-1,000 m, contributing greater spatial resolution of these variables. Approximately 10 species of marine mammals inhabit the waters off Oregon, several of which feed within the region of interest. To obtain marine mammal distribution data within a 1,000 km² area surrounding the OOI cabled and glider instruments, we queried the Ocean Biogeographic Information System (OBIS) database for observations of killer whales, sperm whales and pacific white-sided dolphins. We used physical oceanographic variables from moorings just below the surface and at depth to characterize the seasonal prey habitat of these three species of marine mammals. Although we did not have data to support an assessment of the region prior to the warm water mass of 2014-2015, the years following this event from 2016-2018 were explored for seasonal ecosystem trends.