Spatiotemporal Drivers of Seabird Distribution at the Pacific Marine Energy Center off Newport, Oregon

• Main Author: Porquez, Jessica M.
• Other Authors: Suryan, Robert M., Palacios, Daniel M., Fuentes, Claudio, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University. Graduate School
• Format: Master Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Ocean wave power > Environmental aspects > Oregon > Newport; Sea birds > Effect of energy development on > Oregon > Newport; Phalaropus lobatus; Uria aalge; uria
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/jm214r31c

The central Oregon coast was selected as an ideal site for wave energy development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development of wave energy sites might impact marine birds. We used vessel-based strip transect surveys to detect spatial and temporal patterns of seabirds during 28 surveys of NETS and SETS from 2013-2015. We also conducted 29 surveys along the Newport Hydrographic Line (NHL) (2006-2009, 2013-2015), a cross-shelf oceanographic sampling line that extends 40 km west of NETS. We collected in situ measurements of surface conductivity, temperature and fluorescence to test correlations between spatial variables and seabird abundance. Common murres (Uria aalge) were the most abundant resident species (70%) while sooty shearwaters (Puffinus griseus) were the most abundant migratory species (78%). We identified 7 focal species (common murres, sooty shearwaters, Brandt's and pelagic cormorants (Phalacrocorax penicillatus and pelagicus), western gull (Larus occidentalis), Cassin's auklet (Ptychoramphus aleuticus), and red-necked phalaropes (Phalaropus lobatus), 5 foraging niches and 3 species of interest for analysis. We used non-metric multidimensional scaling ordinations to assess seasonal shifts in the seabird community at a focal species and foraging group level. Both ordinations depicted strong seasonal gradients with distinct seasonal communities. Focal species were also driven by a distance to shore gradient, while foraging niches were more influenced by foraging type (diving versus surface feeding). The shoreward shift or outward dispersal of species appears driven by a combination of factors, including the diffusion of nearshore concentration of murres and cormorants on Yaquina Head post chick fledging, and the inshore movement of migratory species with the onset of upwelling and greater prey abundance. We employed generalized ...