PACIFIC SILVER SALMON 



Oncorhynchus kisutcli (Waibaum) 



Each of the five Pacific sahnon has been introduced into Maine 

 waters at one time or another, but only a few populations of silver sal- 

 mon remain at present. 



Silver salmon were introduced initially into Maine during May of 

 1905. One million, three hundred thirty-six thousand fry were dis- 

 tributed in the Piscataqua, Saco, Kennebec, Damariscotta, Penobscot, 

 Narraguagus, Dennys, St. Croix, Aroostook, Union, and Orland Rivers. 

 Eggs were obtained from the State of Oregon and hatched at the Craig 

 Brook Fish-Cultural Station at East Orland. 



Silver salmon were stocked from 1943 to 1952 in the Pemaquid 

 River, Tunk Stream, Chandler River, Ducktrap River, and Cove Brook 

 to supply an additional fishery in estuaries and streams that did not sup- 

 port runs of Atlantic salmon. One hundred and fifty adults were esti- 

 mated to have returned to the Ducktrap River in November of 1947, 

 and a few were captured. Twenty-one adult silvers were seined and 

 scale samples taken at the mouth of the Ducktrap River in November 

 of 1952. Reports of adult silver salmon in the Chandler River have 

 been checked from time to time but the fish have not been observed by 

 fishery biologists. 



Eleven small silver salmon were taken in the fall of 1956 in the 

 Cove Brook trap operated as part of the Atlantic salmon program. 

 These grilse, or "jacks" as they are called on the Pacific Coast, ranged 

 from 11.1 to 13.2 inches in total length. Four of these fish were defi- 

 nitely ripe males. An interpretation of the growth patterns on the scales 

 revealed that the fish were two-year-olds having spent the first summer 

 following hatching in fresh water and the second year in the marine 

 environment. Lengths and weights of these fish were average and com- 

 pare favorably with those for precocious male silver salmon on the west 

 coast of Canada. The normal life cycle of the silver consists of one year 

 in fresh water and two in salt water. Variations in these periods can be 

 expected. 



Five mature silver salmon were taken at the Cove Brook trap in the 

 fall of 1957. These mature adults ranged from 24.5 to 30.5 inches in 

 total length and from 5 pounds 5 ounces to 9 pounds 5 ounces in weight. 

 The fish were the result of natural propagation and were in excellent 

 shape. Examination of the growth patterns on the scales indicated the 

 average life cycle of three years at maturity. 



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