48 POPULAR SCIENCE MONTHLY. 



THE PAKENT-STREAM THEORY OF THE RETURN OF 



SALMON. 



By President DAVID STARR JORDAN, 



I.ELAND STANFORD JUNIOR UNIVERSITY. 



IT has been generally accepted as unquestioned, by packers and 

 fishermen, that the salmon of the Pacific (king salmon, red 

 salmon, silver salmon, humpback salmon and dog salmon) all return 

 to spawn to the very stream in which they were hatched. As early as 

 18<S0, the present writer placed on record his opinion that this theory 

 was unsound. In a general wa}^, most salmon return to the parent 

 stream, because when in the sea the parent stream is the one most 

 easily reached. The channels and runways which directed their course 

 to the sea may influence their return trip in the same fashion. When 

 the salmon is mature, the spawning season approaching, it seeks fresh 

 water. Other things being equal, about the same number will run 

 each year in the same channel. With all this, we find some curious 

 facts. Certain streams will have a run of exceptionally large or ex- 

 ceptionally small red salmon. The time of the run bears some rela- 

 tion to the length of the stream: those who have farthest to go start 

 earliest. The time of running bears also a relation to the tempera- 

 ture of the spawning grounds — where the waters cool off earliest, the 

 fish run soonest. 



The supposed evidence in favor of the parent stream theory may 

 be considered under three heads:* (1) Distinctive runs in various 

 streams, (2) return of marked salmon, (3) introduction of salmon 

 into new streams followed by their return. 



Under the first head it is often asserted of fishermen that they 

 can distinguish the salmon of difi:erent streams. Thus the Lynn 

 Canal red salmon are larger than those in most waters, and it is 

 claimed that those of Chilcoot Inlet are larger than those of the 

 sister streams at Chilcat. The red salmon of Red Fish Bay on 

 Baranof Island (near Sitka) are said to be much smaller than usual, 

 and those of the neighboring K"ecker Bay are not more than one third 

 the ordinary size. Those of a small, rapid stream near ISTass River 

 are more wiry than those of the neighboring large stream. The 

 same claim is made for the different streams of Puget Sound, each 

 one having its characteristic run. In all this there is some truth and 



* See an excellent article by H. S. Davis in the Pacific Fisherman for July, 

 1903. 



