131 



in addition, nutrient and bjoniass gradients lia\e been measured in various monitoring studies. 

 A similar approach might also be applicable to the assessment of local zooplankton response 

 to phNloplankton population density' increases. This re\'ie\\er would anticipate that the iniie 

 of exposure to enriched ph>1oplankton food sources may be short relatn'e to the time 

 required for zooplanlcton lo sliow significant growth enhancement from a population point of 

 view, befoi;e the\' are dispersed into the background. 



The preparers ha\e presented a reasonable bod>' of exidencc to support the conclusion 

 that the proposed outfall w ill not likeh' aflect regional water column and bottom \\ ater 

 dissolved o>;>gcn content belo\\' established standards. Particulate Organic Marter (POM) 

 from priman' treated eftluent, if transported some 20 km east to Stellwagen Basin, a region 

 of characteristically lo\\'er bottom water DO, may induce respiratoiy consumption of oxygen 

 to be]oA\' State standards. Of interest in this discussion would be an estimate of the nominal 

 and most rapid transpon time of effluent-derived POM to this basin., as the Biological 

 Oxygen Demand (BOD) of this material \\ill signitlcantly decrease in transit. 



The general topic area concerning effects of toxic substances, threshold of toxjcir\-. 

 bioamplification. etc. are not generalh' A\ithin this re\'iewer's area of expertise. Ho^^■e^■er. as 

 far as this re\iewer can tell from a general \ie\\point. the preparers seem to ha\e presented a 

 reasonable case suggesting that outfall toxics \\ill not translate into measurable effects on the 

 endangered species considered. They have relied minimalh' upon modeling b\' addressing 

 expected concentrations to be experienced outside the zone of initial dilution, using 

 concentration values that have been directly measured in the outtall eflluent. 



In conclusion this revie\^er belie\ es that overall the preparers ha\e presented a good 

 case for undetectable effects of the proposed outfall upon the chosen list of endangered 

 species, re!ati^■e to present inputs from Boston Harbor. The major element ^^■orking in fa\or 

 of the outer outfall site is the high rates of mixing and dilution to be expected. Given the 

 le\els and natural \'2nabilirv' in nutrients and \anous substances \\ithin the recei\ing ^^■aters of 

 this site the zone of perturbation wiW likely be quite small and will not be located verv' much 

 closer to the Sielh\a2en Bank ecos\siem. 



