The relative segregation of the spawning 

 groups was apparent from the similarity or 

 dissimilarity of recovery proportions plotted 

 in this way. Groups with substantial contrast 

 could have been already segregated in time 

 of occurrence at Igiugig and might require 

 closer inspection. 



For the statistical analysis, proportions 

 could be readily arranged as contingency tables 

 and tested for independence by the chi-square 

 test. Recoveries from single days of tagging, 

 however, were generally fewer than five in 

 each recovery area. Consequently, recoveries 

 were insufficient to permit tests on a day-to- 

 day basis. Larger values had to be obtained 

 by forming a few adequate units from the 

 many inadequate recoveries from single days. 

 To provide larger units all recoveries were 

 incorporated into four approximately equal 

 divisions of the tagging periods, giving four 

 separate experiments annually. It is empha- 

 sized that the grouping into these experiments 

 was an arbitrary one that was not anticipated 

 when the studies began. Total days of tagging 

 were not exactly divisible by 4 in any year. The 

 remaining days, 1 in 1957, 2 in 1958, (one of 

 which had no tagging), and 3 in 1959 (one of 

 which had no tagging), were arbitrarily as- 

 signed to the fourth experiment. These addi- 

 tional days might have been apportioned to two 

 or more periods in 1958 and 1959, but the 

 final period in each of these years yielded a 

 smaller number of recoveries than did any of 

 the earlier periods. A more even distribution, 

 and from the standpoint of the visual com- 

 parison at least, a more satisfactory block of 

 data was formed in the m^anner described. 



the results and complication in the analysis 

 by considering them separately. A second 

 consolidation was sometimes necessary if 

 recoveries were drawn wholly or in part from 

 personal-use fisheries. The principal fisheries 

 are concentrated on productive salmon 

 streams, but the fishermen may fish wherever 

 they can obtain the number of salmon they 

 need. Except during times of shortage fisher- 

 men stay principally on historic sites, and 

 any recoveries made in their vicinity may be 

 reported as from those sites. It appeared 

 best to describe the general areas of principal 

 fisheries and to treat all recoveries from 

 within those areas as units, bearing in mind 

 the desirability of dealing as nearly as 

 possible with well-defined spawning groups. 



All recovery locations having consolidated 

 data and the sources of their recoveries, e.g., 

 streams and personal-use fisheries, are de- 

 scribed below. The location and relative size 

 of these areas, termed "collective recovery 

 points," are shown in figure 4. 



It is incorrect to consider consolidated re- 

 coveries as wholly representative of particular 

 spawning groups because they include some 

 tagged fish of unknown origin. Thus, all 

 places of recovery are called recovery 

 "points." 



The collective recovery points and the 

 sources of recoveries attributed to them are 

 as follows: 



1. GIBRALTAR: Gibraltar River, the 

 personal-use fishery at the mouth, and the 

 winter village 4 miles east. 



Tag recoveries from certain contiguous 

 areas had to be consolidated. First, in certain 

 areas recovery locations were reported vague- 

 ly. Usually this was because the pond or stream 

 in question was but one of several unnamed 

 ones in the area. Sometimes two or more 

 streams drained an area of spring ponds, and 

 it was difficult to associate spawning salmon 

 with the stream they had ascended. In such 

 instances no purpose would have been served 

 by keeping small numbers of recoveries sepa- 

 rate. It seemed better to consolidate them 

 deliberately than to risk uncontrolled errors in 



2. SOUTHEAST BEACHES: Approxi- 

 mately 12 miles of beach area extending 

 southwest from the mouth of Iliamna River and 

 including the many small streams entering 

 over the beaches. 



3. PEDRO BAY: The personal-use fish- 

 ery at Pedro Bay Village, Pedro Creek, and 

 the small spring ponds near the village. 



4. KNUTSON COMPLEX: The area bor- 

 dered by Iliamna Lake from the head of 

 Knutson Bay westward for 8 miles and the 

 vigorous personal-use fishery at the mouth 

 of Canyon Creek, 



