A Logistic Regression Model for Estimating Turbine Mortality at Hydroelectric Generating Stations
Citation
A. JAMIE F. GIBSON and RANSOM A. MYERS. 2002. A Logistic Regression Model for Estimating Turbine Mortality at Hydroelectric Generating Stations. Transactions of the American Fisheries Society 131:623–633, 2002
Summary
Abstract.—We present a method that allows separation of fish mortality caused by handling and capture techniques from that caused by passage through a turbine. Fish that are naturally entrained into the turbine tube are captured with nets deployed in the turbine tailrace for varying lengths of time. The live or dead status of captured fish is modeled as a binomial response that is a function of the duration of net deployment. Within this model, the intercept is an estimate of the mortality of fish that have spent zero time in the net. For species that do not suffer high mortality from other components of the capture process (such as removal from the net), this intercept may be interpreted as an estimate of turbine mortality. If mortality [...]
Summary
Abstract.—We present a method that allows separation of fish mortality caused by handling and
capture techniques from that caused by passage through a turbine. Fish that are naturally entrained
into the turbine tube are captured with nets deployed in the turbine tailrace for varying lengths
of time. The live or dead status of captured fish is modeled as a binomial response that is a function
of the duration of net deployment. Within this model, the intercept is an estimate of the mortality
of fish that have spent zero time in the net. For species that do not suffer high mortality from
other components of the capture process (such as removal from the net), this intercept may be
interpreted as an estimate of turbine mortality. If mortality from other components is high, the
intercept cannot be interpreted as turbine mortality without correction for mortality from the other
sources. We suggest a modification to the model that allows estimation of mortality from these
components. We demonstrate the method with data for 12 species of fish captured at the Annapolis
Tidal Generating Station, Nova Scotia, Canada. Acute turbine mortality estimates ranged from
0.0% for sea lamprey Petromyzon marinus to 23.4% for American shad Alosa sapidissima.
