47 



• Whereas species abundance estimates were accurate (the good year- 

 dass of haddock was well observed), yield estimates were not; 



• Assessment theory had developed in a manner to require long-term 

 analysis instead of the need to make short-term decisions. 



Broadly, assessments have evolved to provide fishery managers with 

 two types of information: (^'^ 



1. Identification of new fishery resources, location, size, and po- 

 tential yield. Often of species having value elsewhere, such surveys of 

 fisheries resources have been a response to expanding worldwide demand, 

 causing redirection of industry infrastructure efforts into new areas since 

 those currently utilized have been overfished. Also, this effort has been 

 partly the consequence of an attitude that, while ocean resources are 

 limited, those limits, particularly in new areas, have not yet been 

 reached. 



2. Identification of the limits on yield to provide maximum sustain- 

 able yield (MSY) . Although an intensive resource inventory might well pro- 

 vide this information, and ideally should provide this information, it has 

 been separated for two reasons: First,, the time sequence of fisheries, 

 although recently much accelerated, must (a) determine the commercial 

 potential of a population, (b) determine whether and when that potential 



is achieved, and (c) further identify the limits of that potential (there 

 is thus a time lag); and second, that the MSY cannot be determined without, 

 at the present time, an awareness of the fishing effort expended. 



Operationally, expanding fisheries have driven an awareness of what 



