COPPER RIVER INVESTIGATION. 139 



ST. ANNE LAKE. 



St. Anne Lake, whicli lies at the head of the stream bearing the 

 same name, is surrounded by low banks, and at the lower end espe- 

 cially is bordered by swampy and boggy shores. It has the form of 

 a long oval, being 5 or 6 miles in maximum length and a mile or a 

 little more in width. 



The lake is very shallow at the lower end, being nowhere more 

 than 4 or 5 feet in depth and having for the most ]^art a depth of 

 less than 3 feet. The bottom is richly overgrown with water plants, 

 among which the Charas are cons])icuous. At various points growths 

 of different types reach to the surface, making veritable reefs of vege- 

 tation that are favorite feeding grounds for myriads of waterfowl. 

 In the shallow porti(m of the lake fish are very abundant. Large 

 ling cod lay on the bottom within easy reach and could be gaffed 

 without difficulty. Moderate-sized whitefish ]^laye(l about in the 

 open water at middle depth and schools of small fish, probably white- 

 fish, darted away rapidly as the canoe approached the point where 

 they were resting. 



The water swarmed with various aquatic organisms. Plankton 

 animals and plants were so abundant as to be conspicuous to the 

 naked eye and on one of the days (Aug. 21) the lake was covered 

 with a delicate water bloom produced by a minute unicellular alga 

 (desmid). By reason of the aquatic life characterized above, this 

 lake is by all odds the most suitable place seen on the trip for the 

 development of young fish. 



A single dead king salmon was found floating in the lower section 

 of the lake in front of the knoll on which the camp was located. Sev- 

 eral red salmon, nearly ripe, were seen in the outlet creek only a few 

 yards below the lake, but otherwise no trace was found of any kind of 

 salmon in all the stay on the lake. The party rowed along the west 

 shore as far as the head of the lake. The net was ]nit out in deep 

 water at two points in the north half of the lake and caught only a 

 number of large suckers which w^ere about ready to spawn. The 

 east shore seems to be largely, if not exclusively, formed by banks 

 of glacial clay without rocks or stones. The west bank is stony, 

 being made u}) of angular fragments and not composed of rounded 

 or water-worn gravels. Along the stony west shore search was made 

 for evidence of salmon nests, either new or old, and for salmon fry 

 as well as for spa\\Tied-out fish. 



It is perhaps not strange that young salmon were not found, 

 because at this period it is likely that any which might have been 

 present earlier in the year would already have started on their migra- 

 tion downstream to salt water. But despite the fact that fish nearly 

 ready to spawn were seen so near the lake in the outlet stream there 

 was no trace of the fish themselves in the lake and no evidence of 

 their having utilized the territory for spawning purposes pre^dously. 



The water of the lake must produce immensely large quantities of 

 young organisms which serve for food of the salmon fiy. Undoubt- 

 edly these are carried down the outlet stream in considerable num- 

 bers and serve in that way to maintain the fry that are hatched in 

 St. Anne Creek. 



This lake is deserving of further study, and in case it is proposed 

 to set aside any reservations in that section of Alaska, St. Anne Lake 

 should certainly be included because of its remarkable fitness for 

 supporting fish life. 



