ApiipJJH^^*^^^^ 



FIGURE l. — Impacted material can be clearly seen in the gallbladder of affected coho salmon (upper fish). Normal gallbladder (lower 



fish) is shown for comparison. 



TABLE 2. — Occurrence of impacted gallbaldders in Pacific salmon subsampled from saltwater and freshwater rearing areas. 



Date 



Species 



Age 



Feed 



No. of 



fish 

 in lot 



No. of 



fish 



examined 



Percentage of 



fish examined 



with gallbladder 



anomalies 



Environment and site 



Net pens: South Puget Sound 



Net pen: Central Puget Sound 



Net pen: Central Puget Sound 



Net pen: Central Puget Sound 



Net pen: Central Puget Sound 



Freshwater holding pond: lower Columbia River 



Net pen: Research fish, Manchester, Wash 



Net pen: Research fish, Manchester 



Net pen: Research fish, Manchester 



Net pen: Central Puget Sound 



Cultured brood stock: Manchester 



Cultured brook stock: Manchester 



Mature fish returning from sea: Manchester 



Freshwater station: Seattle, Wash 



Freshwater station: Seattle 



Net pen: Research fish, Manchester 



Net pen: Research fish, Manchester 



Freshwater station: Seattle 



Net pen: Research fish, Manchester 



Net pen 4 : Central Puget Sound 



'Oregon Moist Pellet — Commercial product. 

 2 Commercial dry pelleted ration. 



3 Fish fed experimental OMP diet containing single cell protein. 

 4 Pers. commun., D. Weaver, Domsea Farms, Gorst, Wash. 



885 



