286 Alaskan Science Conference 



clam beds in the Territory are those near Cordova. Here, razor 

 clam canning started in 1916, and exploitation of the beds fol- 

 lowed the usual pattern. Excessively large packs were produced, 

 first drawing heavily on the older, larger clams, then when the 

 supply was exhausted, an effort was made to maintain produc- 

 tion by drawing on immature stocks. The results were dis- 

 astrous and in 8 years production dropped to 10 percent of its 

 former peak. Research entered the picture at this point, and 

 precise information was obtained concerning the age and size 

 at maturity, rate of growth, and age composition of the clam 

 population. A minimum size-limit was made effective immedi- 

 ately to protect immature clams until they had an opportunity 

 to spawn at least once, thus assuring a limited breeding reserve. 

 Next, an arbitrary limit was placed on the quantity of clams 

 that could be taken, and studies were commenced to show what 

 effect these control measures had on the resource. The age 

 composition of the catch, and the catch per unit of effort were 

 the guides to its condition. The proportion of older clams in 

 the population increased and the average catch per unit of 

 effort increased. Gradually and cautiously the catch limitation 

 or quota was raised. In time this quota exceeded the surplus 

 stock of the resource, and very soon there was a decline in the 

 relative abundance of the older year classes and a falling off of 

 the catch per unit of effort. The quota was lowered when these 

 danger signals appeared, then when they disappeared it was 

 raised again slowly. For about 10 years now the quota or catch 

 limitation has been constant. It appears that the present quotas 

 assure a sustained yield, but the fishery is under constant sur- 

 veillance for those warning signals that would indicate either 

 need for greater protection or availability of unutilized surplus 

 stocks. 



The Pribilof fur-seal herd is often cited as an outstanding 

 example of resource conservation. Let us examine its manage- 

 ment. 



It was in 1786, 45 years after the discovery of Alaska, that the 

 Pribilofs were discovered and named for the explorer who 

 found them. Ruthless exploitation of the fur-seal herd com- 





