The Okanogan Basin Monitoring and Evaluation Program (OBMEP) monitors the status of habitat, biological, and water quality indicators that affect endangered steelhead populations in the Okanogan River. The seven project types OBMEP conducts to collect various data are:
1. Spawning Surveys
Spawning surveys are conducted on the mainstem of the Okanogan River and all of its tributaries that contain sufficient water to support spawning. The mainstream Okanogan River and all tributaries are observed up to three times each year beginning in mid-march and extending through early May.
2. Rotary Screw Trapping
Rotary screw trapping is used to sample a portion of juvenile salmon and steelhead as they migrate downstream to the ocean. A rotary screw trap consists of a cone 5 – 8 feet across with large rotating blades which funnel fish into a live box. Trapping of outmigrating fish begins in April and ends when their numbers decline to near-zero, which is usually in late July. As of 2012 sampling season, rotary screw trapping will be conducted under the Chief Joseph Hatchery Monitoring and Evaluation Project.
3. Physical Habitat Sampling
OMBEP monitors changes to physical habitats through a suite of indicators sampled at spatially-balanced sites. Physical habitat indicators are measured in mid-July and August at up to 50 locations within the basin each year.
4. Snorkel Surveys
Snorkel monitoring provides an estimate of the egg-to-parr survival of juvenile steelhead in the Okanogan River Basin. Snorkel surveys are conducted in August at the physical habitat sites.
5. Water Quality Sampling
Water quality measurements of temperature, discharge, dissolved oxygen, nitrates, pH, and conductivity also occur at the physical habitat sites in August through September.
6. Invertebrate Sampling
Macroinvertebrates, key indicators of a streams health, are sampled in mid-July and August at each habitat site.
7. Fish Enumeration with Underwater Video
OBMEP maintains and operates several strategically placed video monitoring stations designed to enumerate fish at the Zosel Dam and on select tributaries.