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<br />Squawfish Population Viability Analysis --July 1993 <br /> <br />Page 16 <br /> <br />6 <br /> <br /> <br />y = -.20b + 6.932, r 2 = .934 <br /> <br />5 <br /> <br />.- 4 <br />~ <br />~ <br />~ 3 <br />"- <br />o <br />~2 <br />eo <br />o <br />- <br /> <br />o log(# of cases) <br /> <br />1 <br /> <br />o <br /> <br />-1 <br />5 <br /> <br />10 <br /> <br />15 20 25 <br />Fish Age <br /> <br />30 <br /> <br />35 <br /> <br />Figure 1.7 <br /> <br />One can perform a sensitivity analysis on this pattern. With growth of 10 <br />rom per year, the survival rate is computed as 0.87, while with 20 mm of <br />growth per year, the survival rate is 0.76. <br /> <br />One thing that the good fit of this regression suggests is that adult survival <br />rates are constant with age and size. That is, there is no senescence, nor is <br />there increased survival with larger size. As argued earlier, this is as <br />expected for a poikilotherm that is free of size-selective harvest. <br /> <br />1.14 The Full Leslie Matrix <br /> <br />To move towards an exact parameterization of the Leslie Matrix written <br />down earlier, an assumption is required about age and egg production. It <br />is natural to assume that egg production is proportional to weight and that <br />weight is proportional to total length (L) raised to the third power. Then <br />the Leslie Matrix has the general form shown below. . <br />