MIGRATION OF ADULT SOCKEYE SALMON. 19 
marking done at this station during August so much under suspicion 
that it was considered necessary, in certain phases of the study, to 
disregard entirely the returns. 
It is important to call attention to the fact that the figures given 
in Table 3 can not be accepted as giving any adequate idea of the 
percentage of fish entering from the ocean which are caught while 
passing through the waters where commercial fishing is permitted. 
Several indeterminate factors must modify the percentage of returns 
to such an extent that, while they are reasonably comparable inter se, 
the actual figures give a much-distorted idea of the toll taken from 
the run as it is passing through the Sound and river. Two of these 
factors are especially obvious, i. e.: (1) The figures as given here do 
not include all of the actual returns, since some were omitted on 
account of faulty or incomplete data; the error from this factor, 
however, is not great, approximately 5 per cent; (2) a much more 
important source of error is due to lost tags. There are no means 
of knowing just how many were taken and not turned in. Nor can 
anything more be learned as to the number of tags lost from the 
fish between the time they were attached and the time the fish were 
ey Numerous reliable reports came to us of fish that showed 
splits in the tail fins terminating in holes similar to the one made 
with the leather punch. Apparently the tags had in some manner 
become caught and pulled out. Another possibility is that some 
of the fish were unable to stand the operation necessary to the 
attachment of the tag, more particularly the attendant handling and 
removal from the water. 
All of these factors would tend to increase the percentage of fish 
captured, but obviously there are no means for determining to what 
extent. . 
TABLE 3.—NUMBER or FisH MARKED EacH Day, Totat NuMBER oF RETURNS FROM 
Eacu Day’s MARKING, AND PERCENTAGES OF RETURNS FOR EAcH SrarTIoON, 1918. 
Station A. Station B. Station C. 
prone Re. | Percent Re- | Percent- Re. | Percent- 
Marked. een: be. ce Marked. tacaed: fede 2 Marked. famed. pee: oe ‘ 
Rybyed4 Ok sk 4 1 Sere th Sate tee. CE oe SEER Cee e lethosy sas |ceeeseepspass ce ecee 
ily he PRS el ee Ea nares a4 EERE 4 peas 43 14 32 
1 ERS EE ee eee Pr me Peis eee ea) Ae Ree oe eR 50 19 
Ue cece ccodec 46 16 35 25 P:R PS Se Ee ee 4 pe 
Dae tadtesccet 10 4 40 40 10 25 61 16 26 
534 5 EE 2 10 95 27 28ee | Syeset 2. | ee seeael- cee esse 
74 ee 8 1 12 56 32 76 25 33 
(ee eo 56 4 7 13 DOF \PUIR [seca te cele neces ene 
SE en 2 eee oer 111 45 40 152 48 32 
Dec atacccuss- 98 16 LO Vee ce eee aek ease cal accccescdleceepeqecleoccacscs|accemsane 
28, FUL. 522% 72 15 21 54 27 AO y Ris. cists lag ete s| eee 
ne aa ee 99 20 20 17 3 AS oS ecasacu lemtecteekel comes amis 
b, eae ee 105 24 23 48 20 ADT 42 SSCS ees Cees 
Be. (it Sezacsgte ade 77 12 16 104 46 pV ee [eee See SE ae a 
ei aage meals ie 138 21 15 64 24 felis BEER ORE 4 eee Sic edes 
Bis2d. 4.43 64 8 12 94 44 AD OUST} SS -ReiEE gadeadlaaeteeees 
Senet s cal anwetass|soneecss=|anenaeest 42 18 Ck Tee! REPAIRS st ee a 
Greco eee eee 34 3 Os eosaccsectsccssesschibese tote 164 2 
Wee ee Eck cia an | odaacre o anl Samegaeen 36 11 31 118 14 12 
es os | ao Gu ees ae econ aseleEemianee| sae cas ses|scapte sina 105 25 24 
HS ea oS a Ee A Pa oP 2 a tee 8 ea ee ay Pee ee ee 155 24 15 
TIER ee OE Be SY Sa SS ey i ey ese a San eee 76 16 21 
‘Totalet se 831 147 17.7 836 311 37.3 1,000 203 20.3 
