157 



he f,'J?\f\ Oiitfflll oil Endnngered Species". 



cuieued by Dr. Cftbell S. Dflois, fissociflte Scientist, UHOI. 



><■ of Reuieu: June 3, 1993. 



Ainnary 



T)ie Biological Assessnent presents a strong case Tor the lack 

 ■r impact of t)ie MURA outfall on tlie endangered species of 

 Massachusetts and Cape Cod Bays and tlie food uebs upon uliich they 

 "icpend. A generally conprehensiue reuieu of existing infornation, 

 including recent monitoring studies, uas used to establish a sound 

 lasis for t)ie conclusion that the outfall uill haue a negligible 

 rffect on the endangered species. Although ecological structure 

 ,nd function is expected to be seriously impacted in the immediate 

 -■icinity of tlie outfall (< 1 km radius), this effect uill decrease 

 ;)iarply uith distance from the site due to strong dispersal forces. 

 :tidal and uind nixing). ,. , ... . . _ _ _ ._,..■ 



As pointed out in the Assessment, the impact of the proposed •. .' 

 outfall must be uieued uith respect to that of the existing ■,■•■. 

 .'ischarge. In terms of linear distance, the proposed site is only ; 

 -bout 25x closer to Stelluagon Bank and lOx closer to Prouincetoun. 

 :f the modeling and laboratory studies of Roberts and Signell are ■.>■ 

 r'ccurate, the dissipation uill be much greater at the proposed site 

 -Jian at the existing site and the areal extent of the impact of the 

 proposed outfall uill be considerably smaller than currently exists 

 ^t the present site. 



Uhile I an in basic agreement uith the findings of the 

 Assessment, there are some caveats that must be considered. First, 

 -Jie 3-D modeling studies by US6S are preliminary, and although the 

 ■Assessment states that future "refinements" to the model are not 

 likely to alter the conclusions, the effects of effluent input 

 ieuel, subgrid-scale nixing rate, uind patterns, and influence of 

 3ulf of Maine currents haue not yet been examined and could 

 potentially alter the predicted transport of effluent. Second, the 

 long-term (2Q-30 years) cumulative effects of the outfall on the 

 Bays enuironment uas not addressed. Third, the effect of the 

 proposed outfall uas not considered in relation to environmental 

 impacts of existing offshore seuage outfalls in other areas of the 

 jorld ocean. Fourth, the potential harmful effects of pathogens, 

 such as viruses and bacteria present in the effluent, to the 

 endangered species are not discussed. Finally, the possibility 

 that locally enhanced plankton productivity from the proposed 

 outfall could attract endangered species to the contaminated area 

 uas not considered. 



These caveats aside, I an in basic agreement uith the findings of 

 the Assessnent. Uhen considered in the context of existing versus 

 proposed discharge sites, the likelihood that these issues uill 

 become important is probably small. Overall the novenent of the 

 outfall from the present to the proposed location uill likely have 

 ;T"'ligible consequences for tlie Bays ecology including the 

 t igered species. The issues mentioned above are discussed more 

 fUiiy belou. 



Potential Concerns uith Assessment 



"i. Preliminary modeling - The input levels of effluent to the USGS 

 nodel critically depend on results fron Roberts' laboratory and 



75-454 0-94-6 



