Analog Computer Models of Fish Populations
نویسنده
چکیده
A modern analo~ computer. tol1ether with an X-Y plotter, I provides a means of constructinl1 useful models of commercially exploited fish populations. The model combined conventional exponential fishin~and natural mortality rates with a Gompertz curve of ~owth in wei~ht. By combination of these rates and curve into a sinl1le differential equation. survival curves for successive year classes of fish were ~enerated by the computer and plotted by the plotter. Wei~hts for all year classes present in each season were summed ~raphi cally. Recruitment was determined from a stockrecruitment curve, set into a function ~eneratorof the computer. Yields for each season were calculated by multiplyin~ stock weil1ht by rate of exploitation and were compared with actual yields to test the validity
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