PACIFIC SALMON FISHERIES. 13 



As a result of his investigations up to this point, Dr. Gilbert pre- 

 sented the following conclusions drawn from the data collected: 



1. The sockeye spawns normally either in its fourth or fifth year, the king salmon 

 in its fourth, fifth, sixth, or seventh year, the females of both species being preponder- 

 atingly 4-year fish. 



2. The young of both sockeye and king salmon may migrate seaward shortly after 

 hatching, or may reside in fresh water until their second spring. Those of the first type 

 grow more rapidly tlian the second, but are subject to greater dangers and develop 

 proportionately fewer adults. 



3. Coho salmon spawn normally only in their third year. The young migrate either as 

 fry or yearlings, but adults are developed almost exclusively from those which migrate 

 as yearlings. 



4. Dog salmon mature normally either in their third, fourth, or fifth yeare, the 

 humpback always in their second year. The young of both species pass to sea as soon 

 as they are free swimming. 



5. The term "grilse," as used for Pacific salmon, signifies conspicuously undersized 

 fish which sparingly accompany the spawning run. They are precociously develope(J 

 in advance of the normal spawning period of the species. So far as known, the gnlse 

 of the king salmon, coho, and dog salmon are exclusively males: of the sockeye, almost 

 exclusively males, except in the Columbia River, where both sexes are about equally 

 represented. The larger grilse meet or overlap in size the smaller of those individuals 

 wfiich mature one year later at the normal period. 



6. Grilse of the sockeye are in their third year, of the king salmon in their second 

 or third year, of the coho and the dog salmon in their second year. 



7. The great differences in size among indi\'iduals of a species observed in the 

 spawning run are closely correlated ^\^th age, the younger fish averaging constantly 

 smaller than those one year older, though the curves of the two may overlap." 



Since 1910 Dr. Gilbert has devoted much of his tinier to investiga- 

 tions'' along this line, especially on the sockeye, ^vith most intercstmg 

 and valuable results. 



His observations on the sockeye runs of British Columbia indicate 

 that they consist principally of four and five year fish and that these 

 two classes appear during successive seasons in \ndely differing pro- 

 portions; that each stream has its distinctive race of sockeye, the 

 progeny retiu'ning at maturity to the parent stream; that sockeye 

 try rarely survive when they proceed to sea \\'ithin the year in which 

 they are hatched; and that sea feeding, ^^'ith the consequent rapid 

 growth, is the most important factor in producing early maturity, 

 an equal number of years in fresh water producing comparatively 

 little effect. 



MARKING SALMON. 



A favorite recreation for quite a number of Pacific coast people has 

 been the marking of salmon fry in order to lind out the age at which 

 they return to spa^^^^, the rate of growth, etc. Scattered through 

 the reports of the various State fish commissions, and occasionally 

 in the reports of the United Stat<>s Bun^au of Fisheries, are to be found 

 detailed reports of such markings and the sometimes remarkable 



" Arc at .Maturity of the Pacific r^ast Salmon of the Genns Oncorhvnchus. By Charles H. Gilbert. 

 I'.ullptin, r. S. Bureau of Fisheries, 1912, Vol. XXXU.pp. 21, 22. Washington, 1913. 



'i Contributions to the Life Historv- nf the Sockeye Salmon. (No. 1.) By C. H. Gilbert. Report of 

 Hritish Coliinitna Commissioner of Fisheries for the year ending Dec. 31, 1913. with Appendices, pp. K53-78. 

 Contrlbutiniis to the Life Ilisforj- of the Sockeye Salmon. (No. 2.) By C. H. Gilbert. Uoport British 

 Columbia Commissioner o: Fisheries for the year ending Dec. 31, 1914, with Appendices, pp. Nis-Trj. Con- 

 tributions to the Life History- of the Sockeye Salmon. (No. 3.) By C. H. Gilbert. Report British 

 Columbia Commissioner of FLsherifw for the year endine T)ec. 31, IQl.";, with Appendices, pp. S27-(;4, (i pis. 

 Contributions to the Life History of the Sockeye Salmon. (No. 4.) By C. H. Gilbert, lieport British 

 Columbia Commissioner of Fisheries for the year ending I)ec. 31, 1917, with Appendices, pp. Q33-W, 14 pis. 

 Contributions to the Life Historv of the Sockeye Salmon. (No. 5.) Bv C. H. Gilbert. Report Brifisii 

 Columbia CommLisioner of Fisheries for the year ending Dec. 31, 1918, with .Vpepndiccs, pp. xJft-.W 24 pis. 

 Contribution.s to the Life Hi^torj- of the Sockey.' S;iltiion. (No. fi.) By C. H. Gilbert. Report, British 

 Columbia Commis.sioner of !■ isheries lor the year ending Doc. 31, 1919, with Appeneices, pp. U35-68, 6 pis. 

 VictorU, British ColiunU*. 



