Chapter IX — OCS Development 



With respect to sperm whales and other endangered 

 cetaceans, the Commission noted that the Service had 

 sponsored a workshop in 1989 to assess available data 

 and to determine what additional information was 

 needed to reliably assess the possible effects of 

 offshore oil and gas activities on marine mammals in 

 the Gulf of Mexico. Subsequently, the Service 

 contracted for a series of shipboard and aerial surveys 

 to better determine the abundance, distribution, and 

 habitat-use patterns of sperm whales and other marine 

 mammals in the northern Gulf. The Commission 

 suggested that the environmental impact statement for 

 the proposed lease sales describe these studies and 

 incorporate results obtained to date. Further, it 

 should provide an assessment of the likelihood that the 

 studies will fully meet the information needs cited in 

 the 1989 workshop report. 



With respect to bottlenose and spotted dolphins, the 

 Commission stated that, because of their abundance 

 and distribution, they may be the species most likely 

 to be affected, directly and indirectly, by offshore oil 

 and gas activities in the area. It noted that there have 

 been at least three documented cases of unusual 

 bottlenose dolphin mortalities in the northern Gulf. 

 These events and the extent to which they have 

 affected both the regional population and local sub- 

 populations of the species in the northern Gulf should 

 be described in the environmental impact statement 

 and factored into the analysis of the possible cumula- 

 tive impacts of oil and gas activities in the lease area. 



The Commission suggested that the Service consult 

 with the National Marine Fisheries Service to (a) 

 obtain the best available information on the distri- 

 bution, discreteness, abundance, seasonal movement 

 patterns, essential habitats, diet, and status of impor- 

 tant prey of bottlenose dolphins in and near the 

 proposed lease sale area; (b) determine to what extent 

 bottlenose dolphin populations and sub-populations 

 may have been affected by unusual mortality events; 

 (c) determine to what extent other human activities 

 may be affecting bottlenose dolphins in the northern 

 Gulf; and (d) determine what additional research and 

 monitoring programs would be necessary to assess and 

 verify both the direct and indirect effects of offshore 

 oil and gas activities on bottlenose dolphins. 



In addition, the Commission suggested that the 

 environmental impact statement should identify and 

 assess the possible cumulative effects on the various 

 marine mammals species and populations of unusual 

 high-mortality events, incidental take in fisheries, oil 

 and gas activities in other parts of the northern Gulf, 

 and other human activities. 



The Commission further recommended that the 

 Service consult with the National Marine Fisheries 

 Service and the Fish and Wildlife Service to identify 

 long-term monitoring programs that may be necessary 

 or desirable to ensure that oil and gas exploration and 

 development do not disadvantage marine mammals. 



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