level that results in maximum net productiv- 

 ity. Maximum net productivity is the great- 

 est net annual increment in population num- 

 bers or biomass resulting from additions to 

 the population due to reproduction and/or 

 growth less losses due to natural mortality." 

 (50 CFR 216.3) 



This operational definition of OSP has been used in the 

 course of decisions concerning the status of porpoise stocks 

 impacted by the yellowfin tuna purse seine fishery (Smith, 

 1979) , and the waiver of the moratorium on taking marine mam- 

 mals in Alaska (44 FR 2540-54, 11 January, 1979). 



In 1976, the MMPA was amended by Section 404 of the 

 FCMA to include within the term "waters under the jurisdiction 

 of the United States" the waters of the U.S. FCZ established 

 by the FCMA. 



Endangered Species Act 



Prior to passage of the Endangered Species Act (P.L. 

 93-205, 28 December 1973) the U.S. had become a party to 

 several international agreements concerning various species 

 of fish, wildlife or plants which were verging on extinction, 

 including the Convention on International Trade in Endangered 

 Species of Wild Fauna and Flora. The ESA provided national 

 recognition that species of fish, wildlife and plants which 

 have aesthetic, ecological, educational, historical, recrea- 

 tional and scientific value have become extinct or presently 

 face extinction as a consequence of economic growth and de- 

 velopment without adequate concern for and conservation of 

 such species . 



The ESA recognized that endangered and threatened spe- 

 cies depend for their existence upon the ecosystems of which 

 they are a part. One of the purposes of the ESA was to pro- 

 vide a means for conserving such ecosystems. Other purposes 

 included provision for a program for the conservation of en- 

 dangered and threatened species, and the taking of appropriate 

 action to achieve the purposes of treaties and conventions 

 concerning endangered species to which the U.S. is a party. It 

 was congressional policy that all federal departments and 

 agencies use their authority in furthering the purposes of 

 the ESA and conservation of endangered and threatened species. 



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