1999 

 NATIONAL OVERVIEW 



New insie;ht into the biology of some species is resliaping their stock assessments. For 

 example, an improved understanding of the population structure of several Atlantic tunas 

 is being obtained from genetic studies and from research using biological markers and new 

 tagging technologies. New technologies may also play an important role in enhancing NMFS' 

 capacity to provide more efficient and accurate fish surveys through, for example, the de- 

 velopment ot advanced, integrated acoustic and laser-based systems and sensor platforms. 

 In most cases, the acoustic and laser-based optical technologies are complementary, ad- 

 dressing specific components of an overall assessment problem. For example, an integrated 

 light detection and ranging (IJDAR) system could potentially be developed to survey 

 midwater species, for which the LIDAR system could be used to estimate fish size or iden- 

 tify species, and the integrated acoustic sensor could be used to provide abundance esti- 

 mates from greater water volumes than could be obtained using LIDAR alone. 



In addition to uncertainties in the status of stocks and abundance estimates or trends, 

 there are critical gaps in our knowledge about ecosystem effects on LMR's. These gaps 

 include the effects of environmental variability and changes caused by climate, functional 

 habitat alteration, and long-term environmental degradation. Also included are gaps in 

 knowledge about multispecies interactions. Several recent studies have stressed the need to 

 incorporate ecosystem considerations and multispecies interactions into fish stock assess- 

 ments and management advice. The National Academy of Sciences indicates that in order 

 to restore fish populations and protect ecosystems, it will probably be necessary to substan- 

 tially reduce fishing mortalities on most species (NRC, 1999b). 



Outlook 



Issues of National concern have not changed substantially since Our Living Oceans 

 was first published in 1991. Indeed, it could be said that they have not changed much 

 during the past 2 decades and that they are found in all corners of the world: concerns 

 about overcapacity, overfishing, and the ability to rebuild overfished stocks; bycatch; allo- 

 cation between user groups; management of stocks that straddle different jurisdictions; 

 habitat degradation; fishing interactions with protected species; and the adequacy of scien- 

 tific information in a complex environment. 



Substantial advances have been made, and continue to be made, on all issues. But 

 because each stock has its own characteristics, each fisher\' has its own peculiarities, and 



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