Laserfiche WebLink
<br />Squawfish Population Viability Analysis --July 1993 <br /> <br />Page 14 <br /> <br />if one is not clear about this. A one year time step is appropriate for the <br />squawfish. It has a May-September growth period and then a dormant <br />period. Thus, a time step less than a year would introduce needless <br />complexity. The date of observation is also quite important, for this has <br />the effect of fixing what is meant by "maternity" or "fecundity." Often <br />these get mixed with early survival. <br /> <br />For the analysis to follow, early May is taken as the point of yearly <br />observation. It is important to understand that information supplied at any . <br />other point in the year cannot be used. In May there are no squawfish <br />larvae. There are only small fishes in the range of 80-100 mm--one-year- <br />old squawfish who have survived the first year of life. The element in the <br />top row of the Leslie Matrix, e.g., the term mg, is the rate at which the 8- <br />year-old adults produce one-year-old juveniles in the following year. It is <br />not the same as egg production, though is doubtless related to it. Figure <br />1.6 illustrates this. There are no juveniles in year T. In year T + 1, the <br />one-year-old juveniles are produced by the 7-, 8-, and 9-year-old adults <br />present in year T. The parameter mg shows the relationship between the <br />number of 8-year-old adults at time T and the contribution from them to <br />the number of one-year-old juveniles at time T + 1. In this case mg has the <br />value 1.0. <br />