if the catch of a species was found to be positively correlated with its 

 value a year away, the forecasting model would include, in addition to a 

 constant term, an autoregressive term for 26 lags (biweekly data points), 

 designated A2 6. The resulting models were used to predict the catch for 

 the current year. The forecasted data were compared to the actual catch 

 by using a test statistic with an F distribution: 



s 



Z ( a± - f ± ) 2 /(s-1) 



F calc = *=! (6) 



where a^ = actual data point for time period i 



f^ = forecasted date point for thime period i 

 s = number of time periods forecasted 

 oij = least square estimate of the model variance 



which has (s-1) and (n-p) degrees of freedom where n is the number of 

 observations used to build the time series model and p is the number of 

 terms estimated by the model. 



To determine if the relative proportions of selected important 

 demersal species differed in the current year from previous years (1973- 

 1980), an expansion of the Krumbein and Tukey (1956) analysis of propor- 

 tions was applied to the relative proportions of the 12 most abundant 

 demersal taxonomic groups. A similar approach was used by Briggs and 

 O'Connor (1971). The analysis consisted of using the arcsine square 

 root transformation of the relative proportions and distributing the 

 sums of squares as in the following analysis of variance model: 



X = X + P + Y.. + S„ k + T + (TY) + (TS) ^ + (7) 



*1 + (R*>il + ™ijl + ( RS >ijkl + ( TR )l m + 

 (TRP),, + (TRY)... + (TRS).... 

 klm ij lm l j klm 



11 



