AGE OF HATCHERY AND WILD WINTER STEELHEAD


IN KALAMA RIVER, WASHINGTON


1979 - 1980   





		WILD								HATCHERY








SALTWATER		PERCENT OF 			SALTWATER		PERCENT OF


AGE			POPULATION			AGE			POPULATION


                                                                 








1			 1.5				1			 1.2





2			79.0				2			89.7





3			18.6				3			 9.1





4			 0.9				4			 0.0





                                                                  





Source:  Washington Department of Game, 1980





Note:  The wild population has more adult age diversity.  This life 


history strategy allows the wild population to spread the risk over a 


number of years.  In addition, the wild population produces more older 


and larger adults which provides for more eggs and expands the area 


available for spawning since larger adults can spawn in larger 


substrates.