agencies as well as others who have an interest in 

 the valuable salmon resource of Southeastern Alaska. 



SOURCES OF DATA 



Tlie information compiled in this catalog 

 is derived from a number of sources, both in and out- 

 side of the field of fishery work. A complete list of 

 these sources is given below. 



Alaska Department of Fish and Game. Valuable 

 stream and escapement information is available in 

 reports by research and management personnel. 



Alaska Salmon Industry. Surveys (made by individual 

 members of the industry) are among some of the ear- 

 liest records available. 



U. S. Forest Service . Data on stream characteristics 

 and salmon escapements are available on several 

 streams in records of studies conducted by this agen- 

 cy on the effects of logging on the physical makeup 

 of streams. 



U. S. Geological Survey. Aerial photographs from 

 this agency are the primary source for measurements 

 of stream distances and areas and for valley fea- 

 tures not visible from the ground. These photo- 

 graphs, which are of most of the streams in South- 

 eastern Alaska, were made by the U. S. Navy (Pa- 

 trol Squadron Four) in 1948. 



Local residents. Another source is the descriptive 

 infqrmation on several major streams provided by 

 local residents. 



Fisheries Research Institute. Records are available 

 for each year starting with 1947. Many of the In- 

 stitute research projects have been concerned with 

 precise measurements of physical factors. Data 

 from these projects provide some of the stream de- 

 scriptions and escapement estimates included in this 

 catalog. In 1950 and 1951 the Institute assembled 

 a stream catalog for Southeastern Alaska with all 

 the information then available. It has served as a 

 guide for the present catalog. 



U. S. Coast and Geodetic Survey. Charts used 

 throughout the catalog for standardization of stream 

 location coordinates are from this source. A number 

 of large-scale charts have provided intertidal zone 

 information. The U. S. Coast Pilot (1952. Southeast 

 Alaska, Dixon Entrance to Yakutat Bay, Tenth Edition, 

 544 p. plus charts) is the source of information on vessel 

 approaches to stream mouths and the authority for 

 spelling of proper names. 



U. S. Fish and Wildlife Service. District catalogs 

 of this agency are a major source of stream physi- 

 cal data and salmon escapement records. Escape- 

 ment records from the streams where weirs were 

 operated are actual counts. The FWS stream 

 numbering system is the basis for the numbering 

 system used in this catalog. Information on some 

 of the large mainland streams with headwaters in 

 Canada was obtained from the Canadian govern- 

 ment by the U. S. Fish and Wildlife Service. 



U. S. Federal Power Commission. The report, 

 Woter Power of Southeastern Alaska. 1947, pub- 

 lished with the cooperation of the U. S. Forest 

 Service, provides discharge rates and stream 

 drainage areas, and other information about a 

 number of important salmon streams. 



LIMITATIONS OF DATA 



Escapement estimates obtained by visual 

 means are often limited in accuracy because fish 

 are not seen in turbid water, under overhanging 

 streambanks, or in areas inaccessible to observers. 

 Actual counts throughout the duration of the salmon 

 run past a counting weir or tower are relatively ac- 

 curate estimates of total escapement. However, it 

 is not economically feasible to establish a weir on 

 each stream, and escapement surveys are the only 

 source of information for a large part of the area 

 which must be covered. The value of the catalog 

 as a history of the salmon escapements can be re- 

 alized only if its limitations are fully known. 



Escapement Estimates 



Escapement estimates do not indicate the 

 actual total escapement. At no time are all the 

 salmon in the stream simultaneously, since the 

 spawning run extends over a period of weeks. There- 

 fore, each escapement estimate is an index of the 

 relative abundance at the time of survey. 



The maximum estimate determined by sur- 

 vey methods at about the peak of the run is used as 

 an estimate of the relative abundance of the total 

 escapement. Reliable indices of relative abundance 

 from year to year can be made only if the surveys 

 are comparable. Evaluation of the following factors 

 is necessary to determine the accuracy of the es- 

 capement estimates. 



Observers . --The escapement records are 

 from many different observers. Variability in 

 estimating the number of salmon in a given area by 

 different observers should be considered in judging 



