Tuesday January 17, 2017
Manteca Bulletin–
A scientific study covering 11 years of fish migration on the Stanislaus River underscores how simply sending more water downstream may not be doing endangered Chinook salmon any favors.
Data shows there is a certain threshold for pulse flow volume that if it is exceeded doesn’t improve fish migration. It also points to other solutions such as the placement of the rock barrier at the head of the Old River west of Mossdale Crossing/Interstate 5 in Lathrop that suggests other water management actions that lift the level of dissolved oxygen and such are critical factors in improving fish migration.
The new study by Fishbio — an environmental consulting company with a team of scientists, engineers, and technicians — was published in the current issue of the North American Journal of Fisheries. It finds that “releasing prescribed volumes of water from reservoirs in pulse flows has had a limited effect on stimulating adult salmon migration in the Central valley’s Stanislaus River.”
The data was gleaned from 2003 through 2014 using a weir to force fish heading upstream to pass through near Riverbank to get a precise account of migrating fish numbers.