the uncertainty and range of possible impacts on marine mammals; 

 and (b) identify and describe the steps that will be taken to 

 verify predicted effects and to detect and mitigate possible 

 unforeseen effects on migratory marine mammals and other 

 components of the ecosystem of which they are a part. 



Alaska PCS Mining Program 

 Proposed Lease Sale. Norton Sound 



A lease sale of submerged lands for purposes of mineral 

 exploration and development was originally scheduled by the 

 Minerals Management Service for July 1989. The proposed sale 

 involved 178,282 acres (or 40 blocks), 5 to 22 km offshore Nome, 

 Alaska, in water depths of 20-30 meters. The Minerals Management 

 Service's Draft Environmental Impact Statement (DEIS) on the 

 proposed sale was provided to the Commission and others for 

 review and comment in November 1988. 



The Commission, in consultation with its Committee of 

 Scientific Advisors, reviewed the DEIS and, by letter of 13 

 January 1989, provided comments to the Service. In its letter, 

 the Commission noted that the DEIS provided a reasonably thorough 

 review and analysis of available information regarding possible 

 impacts from fuel spills, acoustic disturbances, dredging, and 

 other activities associated with the proposed action that could 

 affect endangered and non-endangered marine mammals in the lease 

 sale area. However, the Commission noted that the DEIS did not 

 provide a complete evaluation of information on the status of all 

 marine mammal species likely to be found in or near the proposed 

 lease sale area. 



Mining activities of the type and scale envisioned in the 

 DEIS have not been conducted previously in the Alaska OCS region 

 or in Federal waters. In light of the lack of previous 

 experience, the DEIS identified a number of potential mitigation 

 measures that would help ensure that possible impacts on marine 

 mammals and other marine resources were detected and avoided. In 

 its letter, the Commission recommended that these measures be 

 incorporated as part of the proposed action and that the Service 

 consider adopting an additional stipulation to require that 

 discharged mining wastes be shunted directly to the seabed in 

 order to protect surface waters from contamination by fine 

 sediments and dissolved metals that may affect living marine 

 resources. 



Because of uncertainties associated with the mining 

 technology to be used, the volume and levels of pollutants in 

 mining waste discharges, and the total resource potential of the 

 proposed lease sale area, the Commission considered it 

 particularly important to ensure that baseline information and 

 monitoring programs provide an adequate basis for detecting 



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