RSICC CODE PACKAGE PSR-467

1. NAME AND TITLE

SRVAL: Stock-Recruitment Model VALidation Code System.

2. CONTRIBUTORS

Oak Ridge National Laboratory, Oak Ridge, Tennessee through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM3033 (P00467I303300).

4. NATURE OF PROBLEM SOLVED

SRVAL is a computer simulation model of the Hudson River striped bass population. It was designed to aid in assessing the validity of curve-fits of the linearized Ricker stock-recruitment model, modified to incorporate multiple-age spawners and to include an environmental variable, to variously processed annual catch-per-unit-effort (CPUE) statistics for a fish population. It is sometimes asserted that curve-fits of this kind can be used to determine the sensitivity of fish populations to such man-induced stresses as entrainment and impingement at power plants. SRVAL was developed to test such assertions and was utilized in testimony written in connection with the Hudson River Power Case (U. S. Environmental Protection Agency, Region II).

5. METHOD OF SOLUTION

The model samples the simulated striped bass population each year, in the same manner in which the commercial fishermen might, but without error - except when error is intentionally introduced. This sampling process simulates the Hudson River CPUE statistic which is the basis of the ulitities' curve-fitting exercise. The model simulates the population over a long time period (nearly 3200 years). Each such simulation is termed a run. The first 50 years of each simulation are not used to allow time for the population to be influenced by the random variation. Beginning with the fifty-first year the model separates the time series of CPUE values (one value for each year in the model) into 120 groups or replicates, each containing 26 CPUE values. In the same manner in which the utilities process the single 26-year CPUE time series from the real Hudson River, the model processes each replicate. The result of this processing is 12 simulated data sets for each replicate, 11 of which correspond to a particular interpretation or approach which the utilities have applied to the Hudson River data, (e.g., the 5-year lag approach or the eggs on eggs approach) and one of which (the 4-year lag) the utilities have not utilized. The same curve-fitting procedure that the utilities apply to each of the approaches is applied to each of these data sets. This curve-fitting procedure consists of fitting the data set with the Ricker model in a linearized form, which results in a two-parameter curve fit, yielding an estimate of both alpha and beta.

6. RESTRICTIONS OR LIMITATIONS

Maxima of 3196 years total for all simulations, 120 replicates, 30 age-classes including eggs, 26 years per real simulation, 12 different ways of processing CPUE data, 9 lag types per execution and 8 years averaged for lagging purposes. Application of SRVAL to populations other than the Hudson River striped bass would likely require modification of the program.

7. TYPICAL RUNNING TIME

NESC executed the sample problem in approximately 6 CP minutes on an IBM4331.

8. COMPUTER HARDWARE REQUIREMENTS

Approximately 606 Kbytes are required to run the sample problem on an IBM4331 under VM/CMS.

9. COMPUTER SOFTWARE REQUIREMENTS

MVS; VM/CMS

10. REFERENCES

SRVAL, NESC No. 1118, SRVAL Tape Description, National Energy Software Center Note 90-14 (October 26, 1989).

S. W. Christensen, C. P. Goodyear, and B. L. Kirk, "The Impact of Entrainment and Impingement on Fish Populations in the Hudson River Estuary, Volume III, An Analysis of the Validity of the Utilities' Stock-Recruitment Curve-Fitting Exercise and Prior Estimation of Beta Technique," NUREG/CR-2220, Volume III (ORNL/NUREG/TM-385/V3) (March 1982).

S. W. Christensen, B. L. Kirk, and C. P. Goodyear, "A User's Guide for the Stock-Recruitment Model Validation Program," NUREG/CR-2562 (ORNL/TM-8216) (June 1982).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced documents and one 3.5" DOS-formatted diskette which includes Fortran source, JCL, and test case input and output. No executables are included with the package.

12. DATE OF ABSTRACT

February 2000.

KEYWORDS: ENVIRONMENTAL IMPACTS