Fisheries

Merced River Salmon Focus of Research by District and State

Merced Irrigation District is currently conducting research and monitoring projects on the lower Merced River to evaluate the Merced River Development Project's interrelationships with fishery resources. The studies were developed in cooperation with the California Department of Fish and Game. Particular emphasis focuses on the freshwater life history characteristics of Chinook salmon: upstream migration, spawning, egg incubation, juvenile rearing, and outmigration of juvenile fish from the river. The research will continue over a period of 10 years.

The initial effort entails the installation of two large fish traps in the river near Hopeton to capture young fish in order to examine, measure and count them. The traps are monitored daily from January through June, which encompasses nearly the entire salmon outmigration period. Young fish are released back into the river as soon as they are identified and counted. This information is invaluable to assess annual salmon production trends and to help evaluate the success of river management actions and its effects on the species. Research findings further assist water managers and natural resource agencies in determining the most important factors affecting the timing and outmigration of salmon from the river system.

A variety of other studies are underway or planned to evaluate fish habitats in the Merced River that will determine potential measures to increase fish populations. The evaluations also include Merced River Fish Hatchery where Merced ID tags hundreds of thousands of young salmon each year. Some recently completed projects by Merced ID that evaluated spawning gravels (http://www.delta.dfg.ca.gov/afrp/project.asp?code=2000-46) and water temperatures (http://www.delta.dfg.ca.gov/afrp/project.asp?code=2001-08) were funded by the U.S. Fish and Wildlife Service's Anadromous Fish Restoration Program. Monitoring of water temperatures continues throughout the watershed from the upper to lower Merced River, including the reservoirs.

For more information on the Merced River research projects, contact Natural Resource Scientists via e-mail at dvogel@resourcescientists.com.