177 



Review of A.D. Link document entitled "Final Work Plan for Perfonning a Biological Impact 

 Assessment and Related Tasks in Suppxjn of Preparation of an Endangered Species Technical 

 Memo" 



Prepared by Dr. Cabell S. Davis (Associate Scientist, Woods Hole Oceanographic Institution) for 

 Aubrey Consulting, Inc. 



October 27, 1992 



Summary 



A. D. Little proposes to use an extensive literature review together with results of a USGS 

 hydrodynamic model to estimate the effects, if any, of nutrient and toxic chemical inputs into 

 Massachusetts and Cape Cod bays from the proposed MWRA sewage outfall on the endangered 

 species in this region. Consultation with experts in marine mammals, toxic phytoplankton, 

 zooplankton, and toxic pollutants is also proposed. Overall, I found the hypotheses to be so 

 general that they are largely untestable. This generality then reduces ability to eliminate 

 ambiguous findings and reduces the overall adequacy of the proposed impact assessment. The 

 Plan treats the biological environment as static rather than dynamic. Recommendations for 

 improvement of the Plan include more focussed hypotheses, initial literature review to make the 

 plan more specific, the provisional use of field and/or laboratory studies to augment literature 

 information, the use of coupled biological-physical modeling, more specific description of the 

 time-space scales of the study including scenarios for physical forcing of the hydrodynamic 

 model, consultation with a statistician for proper statistical design of the study. It is highly 

 probable that if the Plan is followed in its present form, ambiguous results will be obtained. In 

 my opinion, therefore, the Plan is inadequate in addressing the critical questions under the 

 Endangered Species Act, and the EPA will not be able to use the results to insure that the 

 operation of the outfall pipe will not jeopardize the endangered species. 



Specific comments are provided in the foDowing sections: 



Completeness of Scientific Hypotheses 



.Although the hypotheses are presented in a straightforward and logical manner, as stated, they 

 are too general to be testable. As an example of over-generality, Hj-pothesis Ho4 regarding 

 nutrient-related impacts states that "Changes in phytoplankton community structure and function, 

 due to nutrients from the proposed discharge, will have no discemable effect on the areal or 

 temporal distribution, species composition, patch density, or biomass production of zooplankton 

 communities in the Bays." Well, at present there is no way to determine whether changes in the 

 phytoplankton community will affect the zooplankton population. We know from laboratory 

 experiments and field studies that zooplankton are generalists in their consumption, but we also 

 know that they grow bener on some species of phytoplankton than others. So to test this 

 hypothesis, one would have to be able to accurately predict what the change in the phytoplankton 

 community might be in terms of actual species dominance and then conduct experiments to 

 determine whether the fecundity and growth of the zooplankton populations would be affected. 



