75 



each time they have cooperated with assessment scientists since 196S they 

 have had an area closed to them.^°'^' 



Yet assessment scientists remain subject to the demands of international 

 politics. They realize that foreign fisheries will continue on Georges 

 Bank, that species will continue to be maximally utilized although efforts 

 will now be made to reduce fishing effort. Further, they are driven by 

 domestic and international economics to design models and systems that can 

 predict variable yields to an absolutely precise level . 



Such precision remains impossible. Funding to increase such precision 

 may be a natural outcome of the recent history of modeling efforts, but the 

 relative costs to gain that final thirty percent of accuracy may be excessive, 

 particularly when the need for such accuracy remains undetermined. 



Recognition that modeling has severe limits, particularly when applied 

 to an environment as variable as the marine ecosystem, should be accompanied 

 by a recognition that a major traditional problem with assessments has been 

 enforcement of decisions and accuracy of data. By and large, the methods 

 that have been developed to assess stocks are sophisticated, but they de- 

 pend on data that continues to be suspect and often erroneous. Rather than 

 attempting to design further models, therefore, that seek to incorporate 

 economic effects with biological effects, the following needs are suggested: 



• For short-term estimates of yields, continue with existing methods 

 supplemented by more frequent abundance surveys. 



• Recognize that a major problem has been enforcement in the past, as 

 well as the validity of data; in the future, assessment requires de- 

 velopment of better data gathering systems, particularly regarding 

 catch and effort statistics, possibly through the placement of ob- 

 servers on foreign vessels. 



