8 



early indication of developing signs of gas bubble trauma. I'd like 

 to elaborate on these points. 



Spill for fish passage is not a new concept; it has been the long- 

 standing goal of the natural resource agencies and Indian tribes to 

 provide a safe passage route for fish passing a hydroelectric project. 

 The goal of the agencies and tribes has been to achieve nonturbine 

 passage routes for 80 percent of the fish passing a dam. Spill has 

 long been considered a viable method of project passage; numerous 

 studies have consistently shown that it is the safest route of pas- 

 sage past a dam. 



In the early to mid-1980's, the provision of spill was compatible 

 with the operation of the hydro systems since there was an energy 

 surplus and power operators had excess water. As the region shift- 

 ed from the energy surplus, the issue of spill became more prob- 

 lematic. Spill is presently being implemented according to the Na- 

 tional Marine Fisheries Service Biological Opinion for 1995 with 

 specific restrictions on spill levels imposed by the State limits for 

 total dissolved gas. I'd like to point out that the volume of spill 

 called for through the biological opinion is actually substantially 

 less and has occurred in some past years. 



The National Marine Fisheries Service has made every effort to 

 obtain and consider input from diverse organizations in develop- 

 ment of the 1995 biological opinion. The steps taken in the develop- 

 ment of the spill program represent technical and scientific proc- 

 esses that occurred over several years. The risks associated with 

 spill were analyzed and incorporated into the development of the 

 present spill program. 



In the fall of 1994, the agency and tribal resource management 

 team reviewed all of the available literature and studies to develop 

 an assessment of the risks associated with spill. The risk was 

 measured in terms of trading oft" the benefits to fish by avoiding 

 turbine passage versus the detriments associated with mortality 

 due to increased levels of total dissolved gases. The agencies and 

 tribes concluded that spill is beneficial at levels of total dissolved 

 gas greater than the levels adopted by the National Marine Fish- 

 eries Service in the Biological Opinion. The National Marine Fish- 

 eries Service chose a more conservative level of total dissolved gas 

 based on their concerns regarding the sublethal effects of gas expo- 

 sure. I conclude therefore that the NMFS spill policy is both sci- 

 entifically valid and conservative. 



The 1995 Spill Implementation Program includes both physical 

 and biological monitoring programs. The monitoring program cur- 

 rently being implemented is based on the recommendations of the 

 Expert Panel on Dissolved Gas convened by the National Marine 

 Fisheries Services and on recent research results on signs of gas 

 bubble trauma. 



Research and monitoring recommended by the State, tribal, Fed- 

 eral and private special interest groups and consultants has been 

 incorporated into the monitoring and research programs for 1995. 

 Individual aspects of the present program are being conducted by 

 State, tribal, Federal scientists and independent consultants. Addi- 

 tional research is being conducted in 1995 which will be reviewed 

 and incorporated into future monitoring programs. 



