The mainstem Trinity River is surveyed to recover salmonid carcasses, and to count and map Chinook salmon redds. The distribution of Chinook salmon redds is expected to change in response to rehabilitation efforts of the Program, and the relative run size of natural versus Trinity River Hatchery origin fish.
In 2009, a total of 4,166 redds were counted from September 7 to December 21 with most redds occurring in the upper river, especially early in the survey (Figure). A file, viewable with the free software Google Earth, has been created to show each redd location surveyed in 2009 and is available at:
For updates, please visit http://www.fws.gov/arcata/fisheries/projectUpdates.html#SpawningSurveyData
Suggested further reading:
May, C (2007) Assessing the risk of redd scour on the Trinity River.
Kautsky, G (s.d.) Results of mainstem spawner surverys conducted in 2004 by Hoopa Valley Tribal Fisheries Department.
Garrison, P (2002) 2000-2001 annual report, Trinity River tributaries winter-run steelhead spawning survey report, project 1d1.
Evenson, D F (2001) Egg pocket depth and particle size composition within chinook salmon redds in the Trinity River, California.
Dean, M (1995) Snorkel and redd surveys of spring chinook salmon in the South Fork Trinity River (1995 season).
Miller, E E (1975) A steelhead spawning survey of the tributaries of the upper Trinity River and upper Hayfork Creek drainages, 1973.