|
Living With the Methow River Monthly Activities and Learning Opportunities December 2014
Salmon recovery groups are required to count fish each year to determine whether recovery efforts are producing measurable benefits. But have you ever wondered how people count fish? Visual counting at fish ladders and weirs used to be the best source of information on returning salmon and migrating juveniles, but this method was subjective and had obvious limitations of scheduling, daylight, and water clarity. Agencies and groups throughout the Methow and the Columbia River basin now use Passive Interrogation Tags (PIT) to track fish. 8 or 12mm tags are inserted in juvenile or adult fish. When these tagged fish swim over an antenna, the data logger connected to the antenna reads the unique number of that tag and records it with the time and date. The Columbia River PIT Tag Information System maintains a database of all PIT tag data from the Columbia Basin, including any recorded fish data such as species, age, weight, length, hatchery vs wild origin, and all tagging and recapture events. Anyone who is interested can access this information at http://ptagis.org/ and search for specific fish and antenna systems.
Two antenna arrays search for passing PIT tags The data from these antennas can answer many questions, including the timing of juveniles migrating downstream to the ocean, the age of migrating fish, the arrival of adult salmon and steelhead to their spawning grounds, as well as how many of the returning fish are wild and how many are from hatcheries. In small tributaries, PIT tag antennas can help groups monitor and document fish passage over improved irrigation diversions and use of improved habitats. For the Methow Salmon Recovery Foundation, Grace Watson is the face of fish counting. She develops the monitoring program, coordinates the data collection devices, and reports the data that allows the group to gauge the effectiveness of past projects and identify areas for future work. For more information, please contact her at (509) 997-0028, extension 3. (The contact info supplied in the print calendar is outdated.)
This year’s MRC calendar connects to ADVENTURES, ACTIVITIES AND INFORMATION tailored to each month. If you haven't gotten your calendar yet, you can download an electronic version here. Come back each month and find interactive activities, print outs, and suggested learning opportunities in our community.
Just follow the fish for more information!
Previous Learning Opportunities: |
