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assessment? Failure of the Work Plan to define 'primary nutrients* 

 perpetuates the subjective, non-rigorous approach intrinsic in this document, 

 and inconsistent with the needed quantitative rigor needed for the ESTM. It 

 is well established that nutrient turnover times must be considered in 

 assessment of nutrient - phyopiankton relationships. Will such 

 considerations be included; the Work Plan appears to leave this decision up 

 to the evaluators. 



Will estimates of carbon flux to depth and potential accompanying 

 hypoxic and/or anoxic effects in the benthic habitat be evaluated? While 

 there is appropriate focus on phytoplankton and zooplankton in the Work 

 Plan, there is conspicuous avoidance of requesting benthic impact 

 assessment. Given the well known association between nutrient loading 

 and bottom water oxygenation, and the dependence of some of the potential 

 endangered species on the benthic habitat and biota, this omission in the 

 Work Plan is curious. 



The biological impact assessment is to evaluate the likelihood of each 

 of the potential linkages'. However, the requirement that this be 

 accomplished by 'comparing data from the scientific literature on threshold 

 effect concentrations to both measured and predicted environmental 

 concentrations' presents a major problem: i.e., the concept of a 'threshold 

 effect'. This concept, which is repeatedly invoked (pp. 8,9,11), is the central 

 theme of this Work Plan and the yardstick by which potential impact is to 

 measured against. 'Threshold effect', however, is not defined; it is 

 traditionally a single species response parameter, whereas the assessment 

 of endangered species impacts requires a trophodynamic and community 

 approach. Threshold effects should be based on experimentation, but there 

 is a conspicuous lack of such data of the type required. Moreover, the type 

 of experimentation needed to derive threshold effects must incorporate 

 effects of factor interactions, including synergistic effects; consider different 

 iife cycle stage responses, etc. It will be very difficult to apply the 'threshold 

 effed' approach called for in the Work Plan and vitiates the entire effort to 

 fulfill the required impact assessment. The proposed use of the USGS 

 model is commendable. However, the apparent lack of a specific biological 

 model to be used as the basis for establishing which trophic processes and 

 transfer steps between trophic levels (beyond the vague hypothesis 

 generalizations in Section 2.3.1) is a serious limitation. Such guidance is 

 essential to defining what specific parameters and processes need to be 

 quantified and included in the biological impact assessment. Presently, this 

 determination is to be made by the evaluators, a subjectivity inconsistent 

 with ESTM needs. 



Predicted Effects of Primary Nutrients on Endangered Species (2.3.1) 



Seven questions are posed in this section of the Work Plan, five of 

 which can be responded to based on available information and phrasing of 

 the questions. 



ft1. Will primary nutrients in the discharge discernably increase levels 

 outside the mixing zone? Ans: Probably. 



