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



665 



MRFSS 1996 samples 



Bluefish 



Observed 

 Lognormal 

 Poisson 

 Neg. binomial 



Observed 



— a — Lognormal 

 — ■• — Poisson 

 — •— Neg, binomial 



12 3 4 5 6 7 



Catch number per hour (including zero catches) 



Figure 7 



Observed and expected catch number per hour (including 

 zero catches) frequency distributions for bluefish, summer 

 flounder, Atlantic cod, scup, and all species, Maine to the 

 Florida east coast. The 9 fish intervals is a "plus group" 

 because it includes totals for larger intervals. 



MRFSS 1996 samples 



Bluefish 



Observed 



- ^ — Lognofmal 



- -• — Potsson 



—  — Meg binomial 



Scup 



Observed 



- -A — Lognormal 



- -• — Poisson 

 -•— Neg. binomial 



— Obsen/ed 



— Lognormal 



— Poisson 

 Neg. binomial 



0123456789 



Catch number per hour (positive catches only) 



Figure 8 



Observed and expected catch number per hour (positive 

 catches only) frequency distributions for bluefish, summer 

 flounder, Atlantic cod, scup, and all species, Maine to the 

 Florida east coast. The 9 fish intervals is a "plus group" 

 because it includes totals for larger intervals. 



Simulated recreational fishery catch rates 



The eleven simulated distributions of catch per trip had 

 means ranging from 2.80 to 0.98 fish per trip, variances 

 ranging from 31.81 to 4.39, and CVs of about 200%. Simu- 

 lated variance decreased as the simulated mean decreased 

 because the negative binomial dispersion parameter, k, was 

 held constant at 0.23. The resulting unstandardized, simu- 

 lated index of abundance declined by 65'7( over the 11 year 

 series (Table 9). 



All standardization model fits were highly significant 

 (P<0.001), as characterized by the chi-square statistics for 

 the year effect (Table 10). The three different time series 

 trends had no effect on the results, and therefore only the 

 results for the decreasing series are reported. The Poisson 

 and negative binomial models generated year coefificients 

 as standardized indices of abundance that were very simi- 

 lar to each other and, as expected, virtually identical to the 

 unstandardized annual means, indicating a 65% dechne 

 over the time series (Fig. 9). Interestingly, the diagnostic 



