660 



Fishery Bulletin 101 (3) 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 



llAM^ 



Summer 

 flounder 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 



Scup 



ll«-i — f- - 



-m- — — » 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 

 Catch number per trip (Including zero catches) 



Figure 1 



Marine Recreational Fishery Statistics Survey (MRFSS) 

 1996 sample data for bluefish, summer flounder, Atlantic 

 cod, scup, and all species, Maine to the Florida east coast: 

 catch number per trip (including zero catches). The 15 and 

 50 fish intervals are "plus groups'" because they include 

 totals for larger intervals. 



Il 



MRFSS 1996 samples 



Bluefish 



1 



lu. 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 



Summer 

 flounder 



12 3 4 5 6 7 



ll 



9 10 11 12 13 14 15 



Atlantic 

 cod 



1«1 



U^ 



^A 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 



Scup 



llll.li.i-l... I.-I.l ^ 



10 



20 



50 



j 



b 



All 

 species 



1^ 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 

 Catch number per trip (positive catches only) 



Figure 2 



Marine Recreational Fishery Statistics Survey (MRFSS) 

 1996 sample data for bluefish, summer flounder, Atlantic 

 cod, scup, and all species, Maine to the Florida east coast: 

 catch number per trip ( positive catches only). The 15 and 50 

 fish intervals are "plus groups" because they include totals 

 for larger intervals. 



observations of catch per trip (including zeroes) for year 

 1 (n = 1000). The initial mean for year 2 was then set at 10 

 percent less than year 1 (i.e. 2.7) and the year 2 set of 1000 

 observations generated under the negative binomial as- 

 sumption. The dispersion parameter, k, was held constant 

 at the year 1 maximum likelihood estimate of 0.23, result- 

 ing in a decrease in variance, a relatively stable coefficient 

 of variation (CV), and less frequent occurrence of large 

 catch-per-trip values, as the mean decreased. These condi- 

 tions were felt to best reflect the true changes in angler 



catch per trip as stock abundance declines. The exercise 

 was repeated for years 3 to 11, providing a time series of 

 decreasing simulated recreational fishery catch per trip. 

 The simulated annual distributions, scaled (normalized) 

 to the 1 1-year time series mean of 1.75, were re-ordered to 

 create the increasing and peaked time series. 



Standardized indices of abundance were then calculated 

 from the simulated, trended series by using lognormal, Pois- 

 son, negative binomial, delta-lognormal, and delta-Poisson 

 models, with year serving as the single classification vari- 



