Terceiro: The statistical properties of recreational catch data off the northeastern U.S. coast 



663 



Results 



Descriptive statistics for MRFSS catch rates 



Descriptive statistics of MRFSS catch rates for the four 

 catch rate configurations, four individual species, and for 

 all species are presented for the years 1981, 1988, and 1996 

 (Tables 1-4). These three years are characteristic of the 

 1981-2002 time series of MRFSS data. Given the similarity 

 among these years, frequency distributions are plotted only 

 for 1996 (Figs. 1-4). Catch rate means, both with and with- 

 out zero catches, are generally much higher than medisms, 



variances are much larger than the means, skewness is 

 always much larger than zero, and there is a high propor- 

 tion of zero catch and one-fish catch-rate observations. In 

 all cases, the Kolmogorov-Smimov D test statistics were 

 significant at the 1% level. All of these factors indicate that 

 MRFSS catch-rate distributions are highly contagious and 

 overdispersed in relation to the normal distribution (Sokol 

 and Rohlf, 1981). Scup has highest frequency of high catch 

 rates (Figs. 1-4). The scup and Atlantic cod samples exhibit 

 modes at regular intervals of high catch-per trip rates (e.g. 

 10, 15, 20, 25, and 30 fish per trip) that may indicate some 

 degree of digit bias in the sampling. 



