185 



longer use these to the same degree tliey did in past decades, or the 

 last century, and this whale has become a \ery serious predator on 

 5'oung sockeye salmon coming down from the streams in Bristol Bay 

 in the spring of the year, and they take thousands of young salmon 

 migrating to the sea from the fresh water. 



So there is a predator problem. Mr. Pelly. I am not prepared to say 

 that this is a terribly serious one. but it does indicate, in my judgment, 

 the need to provide some kind of balance in the ecological system as 

 mentioned by Mr. Talbot. 



Studies on fur seals show that as salmon congregate and concentrate 

 in the spring of the year, one of the major foods of fur seals at that 

 time is the salmon. 



Toothed whales and fur seals do feed on salmon but, of course, now 

 that the population of fur seals is held in control. I think it is the view 

 of the scientists that this predation on the important salmon stocks of 

 Alaska and the Pacific Northwest by fur seals is not serious. 



]Mr. Pelly. Would it be possible for you. with the permission of the 

 chairman, to submit for the record a list of the various marine mam- 

 mals, with your comments as to any danger to fishery resources, if 

 they were not controlled under some suggested plan such as a flexible 

 plan which Dr. Talbot suggested tliis morning ? 



^Ir. McKerxax. I will be happy to cooperate with the committee. 



(The information follows :) 



Marine Mammals Control 



Almost all marine mammals are carnivorous. Many species, notably various 

 species of seals and whales, including porpoises and dolphins, are known to 

 consume some quantities of fish used for food by humans. We know, for example, 

 that fur seals eat salmon although tlie major part of their food appears to 

 consist of other, less desirable species. Hair seals also take salmon, and beluga 

 wha'es take, in addition to maturing .salmon, .some quantities of salmon smolts in 

 Bristol Bay during the outward migration of the smolts. Baleen whales, of 

 course, usually subsist on smaller organisms not generally sought by man but 

 which are part of the food supply for fish higher in the food chain. 



Unfortunately, to the best of my knowledge there is little evidence as to the 

 physical quantities of useful fish that these mammals consume. As to controls 

 over the populations, there are. of course, controls over fur seals and the larger, 

 commercially exploited whales. The native population in Alaska takes walrus, 

 some hair seals and a few of the smaller whales, like the beluga. Otherwise, the 

 populations of these mammals, at least off the United States coast, are controlled 

 mostly by the circumstances of their natural environment. In summary, it can 

 only be said that marine mammals have some adverse effect on stocks of useful 

 fish. The degree of this effect is not known, but it will obviously vary with the 

 size of the populations of mammals. 



Mr. Pelly. Thank you 



Mr. DixGELL. ]Mr. Anderson ? 



Mr. AxDERSox'. Thank you. Mr, Chairman. 



Has the State Department tried to negotiate any other treaty simi- 

 lar to tlie fur seal treaty of 1911 with respect to some of these other 

 marine mammals like the walrus, the sea otter, and so on ? 



