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techniques for gas bubble disease symptoms, gas measurement, and data 

 recording. The crews at both locations lacked confidence and precision in at 

 least some aspect of what they were doing. 



A fish health specialist and appropriate equipment should be added to each 

 crew. This will ensure that appropriate decisions are made in the event of non- 

 standard occurrences. As your crews stated to Ken and Jerry, exception seems 

 to be the standard. 



Larger test fish should be used, perhaps yearling steelhead, to make the 

 examination of symptoms easier. The subyearling chinook are difficult to 

 examine, because of their small size, and bubbles are easy to overlook. 



The live cages below Bonneville Dam should be moved to a location which 

 receives more direct inflow from the spill plume. Your crew has noted that 

 saturation levels tend to run about 2% lower near the live cages than in the main 

 current of the river. 



FISH PROCESSING PROTOCOL 



► The field technicians for your GBD monitoring project urgently need a written, 



detailed protocol on how they are to deal with handling fish during initial capture, 

 transport to the live cages, placement into the live cages, and recovery from the 

 live cages. Your crews monitoring the live cages below Ice Harbor Dam and 

 below Bonneville Dam had a good general idea of vA\ai to do, but had to fill in 

 the details based on their own judgement Since they are not trained fish 

 biologists, nor are they trained in the physiology and identification of all gas 

 bubble disease signs, they unknowingly choose some procedures that bias the 

 results. 



Whenever MS-222 is used for anesthetizing fish, it should be buffered to prevent 

 harm to fish from high acidity. 



«• Handling of hatchery chinook transported to the live cages should be minimized. 



These fish were anesthetized and measured prior to placement in the live cages 

 at Ice Harbor. Is this really necessary, since these fish get measured at the 

 conclusion of the test? 



- Fish should be examined within 1 5 minutes of being removed from the river or 



live cages. We observed that fish at both locations were held up to two hours 

 after being euthanized, before they were examined This delay allows for some 

 bubbles to redissolve, such that the number of fish with GBD signs would tend to 

 be underestimated. 



