The abundance and distribution of harbor seals and steller sea lions in Oregon

• Main Author: Pearson, John Philip
• Other Authors: Verts, B. J., Fisheries and Wildlife, Oregon State University. Graduate School
• Format: Master Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Seals (Animals); harbor seal; Phoca vitulina
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/fx719q266

The abundance and distribution of the Pacific harbor seal (Phoca vitulina richardi) and the northern or Stellar sea lion (Eumetopias jubata) in Oregon are described, The number of seals and sea lions presented for bounty in Oregon since 1925 is presented. Based on periodic surveys conducted between December, 1967 and June, 1968, numbers of harbor seals in Oregon were estimated to be not more than 500 in 1967-68 and most were found outside estuaries on offshore islands. However, a population of harbor seals in excess of 2,000 was once found in Oregon. Simpson Reef, Hunter's Island, Rogue River Reef, and Gull Rock were locations of the major concentrations of harbor seals in Oregon. The Columbia River, once attested to have the greatest number of seals in Oregon, now has no year-around resident seals, and the number of seals entering the river or remaining in the river for extended periods appears to be at an all-time low. Numbers of northern sea lions in Oregon were estimated to be about 1, 000 in 1967-68. There were two breeding colonies or rookeries in Oregon, the largest on Orford Reef 3nd the smaller at Sea Lion Caves. Other locations used by sea lions included the Rogue River Reef, Simpson Reef, Three Arch Rock, and Tillamook Head. Since Kenyon and Scheffer (1953) previously estimated the sea lion population of Oregon to be 1,000 animals in 1953, it was concluded that the population in Oregon was relatively stable. However, the current population was considerably smaller than 1925-27.