• Background
• Objectives
• Information Use

Experimental Variables

Fish Collection

Fish Care

Experimental Protocol

Measurements

Reports

Research Staff

Funding Sources
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

The Fish Treadmill Project of the University of California, Davis 

Introduction 

Background
     The fisheries resources of the Sacramento-San Joaquin Delta system have been recognized as valuable state resources for several decades. A number of fish species, including the endangered winter-run chinook salmon and the threatened delta smelt have been jeopardized by the increased water demand by agricultural, domestic, municipal, industrial, and recreational users of California.  State law provides the California Department of Fish and Game (CDFG) the authority to require installation of fish screens on water diversions to reduce fish losses. Kano and his colleagues (1982, Interagency Ecological Study Program for the Sacramento-San Joaquin Estuary, Technical Report no. 4), examined survival of fishes exposed to controlled flow regimes and fish screens like those at water diversions.  However, many technical, biological, and environmental problems related to diversion design and operation in the Delta have not been resolved.  To address these questions, the Fish Facilities Technical Committee of the Interagency Ecological Program proposed the Fish Treadmill Project in order to determine:
a) how Delta fish species of various sizes and swimming abilities might behave if subjected to a screened barrier adjacent to the river; and 
b) the suitable approach velocity and screen exposure duration for various fish species.

     In 1994, the Hydraulics Laboratory of the University of California, Davis (UCD), headed by Prof. M. Levant Kavvas, was contracted to design and construct a small-scale fish treadmill model as well as a full scale fish treadmill prototype.  The apparatus was designed to provide controlled, relatively uniform flow regimes, at levels similar to those currently required for screened water diversions, in a relatively large volume, annular flume or swimming channel in which fish could be confined and their responses to the flow and screen observed and quantified.  Upon completion of the Treadmill prototype in 1997, the UCD Fish Physiology Group, headed by Prof. Joseph J. Cech, Jr., began biological studies to evaluate the performance and behavior of selected Delta fishes in the apparatus under a range of biological and environmental conditions.

Objectives
     Biological studies are conducted to evaluate  Delta fishes' swimming performance, and behavioral and physiological responses to exposure to a two-vector flow field with a screened barrier.
    Objective 1. Evaluate and quantify the performance (i.e., survival, screen contacts, impingement) of selected Delta fishes exposed to two-vector flow regimes and environmental conditions (e.g. temperature, light level) similar to those that occur near fish screens in the Delta and local riverine systems.
   Objective 2.  Evaluate and quantify the behavior (e.g., orientation to current, swimming velocities, distance traveled) of selected Delta fishes exposed to two-vector flow regimes and environmental conditions (e.g. temperature, light level) similar to those that occur near fish screens in the Delta and local riverine systems.
   Objective 3.  Evaluate and quantify the physiological responses (e.g., blood hematocrit, plasma cortisol and pH levels) of selected Delta fishes exposed to two-vector flow regimes and environmental conditions (e.g. temperature) similar to those that occur near fish screens in the Delta and local riverine systems.
   Objective 4.  Compare the performance, behavior and physiological responses of the tested fish species to to determine differential vulnerability to entrainment and impingement at fish screens. 
   Objective 5.  Compare results from these studies with those conducted by Kano (1982). 
   Objective 6.  Compare results from these studies with present fish screen and flow criteria specified for the Delta and local riverine systems.
   Objective 7.   In collaboration with state and federal agency personnel, suggest refinements for present fish screen flow and operational criteria for each of the tested species.

Information use
      Results of these studies are provided to state and federal agency personnel as annual and final reports for their use in evaluating and revising present fish screen flow and operational criteria to better protect fishes in the Delta and riverine systems and reduce losses due to entrainment and impingement. Results are also reported in Interagency Ecological Program Newsletter articles, presented at interagency workshops and scientific meetings, and will be submitted for publication in peer-reviewed scientific and management journals for wide dissemination.