Seasonal Movements and Population Trends of Harbor Seals, 'Phoca vitulina richardsi' in the Columbia River and Adjacent Waters of Washington and Oregon: 1976-1982

摘要

Methods for capturing, handling and tagging harbor seals were developed and used in the Columbia River. A total of 96 harbor seals were successfully captured and tagged using methods described. Daily activity and movement patterns of seals were monitored with the aid of radiotags and pelage marks. Radiotelemetry packages were attached to seals using either an anklet (for adults), or glued to the pelage using epoxy. Harbor seals interchange and movements were recorded between Columbia River haulout sites and adjacent coastal and estuarine haulout sites. Using total coverage aerial censusing of the Columbia River and adjacent areas, the regional harbor seal population was estimated at 6,000-7,000.