Abstract
Fisheries of “iwasi” in the Inland Sea have been, in the previous report, classified into three types by analysing secular variations of yield as problems of time series and corelogram. In this report, the writer treats fluctuations of catch in each type with relations to factors of environments-oceanographical and meteorological conditions.
Patterns of annual variations of sea water temperature and specific gravity at several stations may be characterized by parameters of the patterns, as shown in Tables 1, 2, 3 and 4. In Tables 5 and 6, are shown coefficients of correlation between fluctuations of catch in each type and factors of environments.
And moreover, problems of predictions have been discussed in the point of view of interpolation by correlation diagram and extrapolation by corelogram. Fig. 1 shows the correlation diagr m between x, fluctuations of catch in type 1, and parameters b, coefficient of linear regression of specific gravity obtained at Kasaoka every two years before the period under consideration. Because of this relation, values of x are possible to be estimated from value of b two years before by means of interpolation.
In Figs. 2, 3 and 4, full and dotted lines, show secular variations of actual catch and calculated values by means of extrapolation from corelogram of time series, respectively. Shaded parts indicate confidence intervals of about 70%.
Above-mentioned relationships have been discussed only in static and apparent states of phenomena. However, dynamical treatments of relationships between parameters of aquatic resources, as well as research upon cause of discrepancies between actual and predicted values of catch, are important subjects which will be studied in future.
