US Army Corps of Engineers, OR

Harris Environmental evaluated the status of the Columbia River Estuary population of nesting double-crested cormorant for the USACE, Portland District. This effort supported the USACE management plan to reduce predation of juvenile salmonids in the estuary. The enumeration and monitoring work was primarily conducted by field and photogrammetric surveys that use high resolution stereo imagery technology. General reconnaissance by boat and aircraft was used to supplement the detailed field and photogrammetry surveys in areas of limited visibility. Reconnaissance was also conducted to identify key loafing and roosting areas, and identify new nesting areas. This project had a very tight time frame, with little flexibility for field work delays. We established a new and efficient methodology using remote sensing to estimate nest counts and to distinguish between cormorant species. We incorporated GIS technologies to plan fieldwork, map nesting sites, and produce reports. We ensured data collected with these new methods met project needs and maintained compatibility with past nest location studies to allow direct comparisons to previous results.