Salmon Recolonization

antennas on Rock Creek

Antennas on Rock Creek used to detect salmon implanted with Passive Integrated Transponder (PIT) tags. The PIT tags and antennas allow researchers to determine survival rates of juvenile coho salmon living in Rock Creek and when they initiate their migration to salt water.

Following completion of the Landsburg fish passage project in 2003, Chinook and coho salmon acquired access to stream habitat upstream of Landsburg for the first time in over 100 years. To evaluate the effectiveness of the fish passage project, a monitoring and research project of salmon recolonization in the watershed is being conducted collaboratively by SPU, NOAA Fisheries, and the University of Washington scientists.

The research began with collection of data on resident fish populations and aquatic ecosystem characteristics prior to fish passage from 2000 to 2002. Since 2003, the study has been evaluating a number of different aspects of the salmon recolonization process, including numbers and characteristics of fish passing through Landsburg, spawning locations and timing, interactions with resident fish, growth and survival of juvenile salmon, and effects of salmon carcasses on stream ecosystems.

Genetic identification of all spawning adults passing Landsburg provides the basis to distinguish fish born above Landsburg from strays born elsewhere. This information can be used to estimate the growth rate of the Chinook and coho salmon populations above Landsburg.

Read more about the salmon recolonization project on the Seattle Public Utilities Cedar River Biodiversity website.