ABUNDANCE OF CONNECTICUT RIVER SHAD 



251 



FISHING EFFORT AND CATCH, 1935-51 



The total fishing effort in terms of standard- 

 fishing-unit days has been determined for each 

 year for the period from 1935 to 1951, inclusive. 

 The total catch for each of these years was 

 obtained from reports submitted by the fishermen. 

 For 1938 and the years 1942 to 1951, the reports 

 on file in the office of the Connecticut State Board 

 of Fisheries and Game supplied a record of the 

 catches made by the commercial types of gear. 

 For the years from 1935 to 1937 and 1939 to 1941, 

 for which the individual reports were not on file, 

 but for which records of total catches are available 

 at the State Board of Fisheries and Game, an 

 adjustment for the proportion of catch taken by 

 noncommercial types of gear was made by sub- 

 tracting 3 percent of the catch from the amount 

 given in table 1 . As pointed out earlier, in no one 

 year for which all the individual reports are 

 available was more than 3 percent of the total 

 catch made by noncommercial types of gear. 

 From 1935 to 1937 and from 1939 to 1941, the 

 numbers of noncommercial types of gear operated 

 were no greater than in tbe other years. 



Table 4 shows the total catch, total fishing effort, 

 and catch per unit of effort for each year from 1935 

 through 1951. The figures entered in this table 

 represent the catch and effort data for the Con- 

 necticut River shad fishery for this period. I 

 should like to remind the reader that the figures 

 for fishing effort for 1935, 1936, and 1937 are 

 estimates made from the information available. 

 Figure 1 shows the curves for catch, fishing effort, 

 and catch per unit of effort for the 17-year 

 period. 



Table 4. — Total fishing effort and catch, and catch per unit 

 of effort, Connecticut River shad fishery, 1935-51 



Year 



Number of 



standard- 



fishing- 



unit days 



1935,. 

 1936.. 

 1937. 



1939. 



1943. 



1945. 

 1946. 

 1947. 



1950. 

 1951. 



1,617 

 1,504 

 1,730 

 1,918 

 1,767 

 1,265 

 1,231 

 1,298 

 1,845 

 2,554 

 3,764 

 5,309 

 5,146 

 4,118 

 3,692 

 2,749 

 2,589 



Number of 

 shad taken 



124, 263 

 106, 459 

 115, 246 



125, 356 

 110, 572 



92,832 

 121, 405 

 114,821 

 169, 356 

 211,963 

 216, 886 

 299, 786 

 218, 990 

 177, 232 

 130, 595 



77, 090 

 100, 967 



Number 

 of shad 



taken per 



s. f. u. 



day 



77 

 71 

 67 

 65 

 63 

 73 

 99 



S3 



58 

 56 

 43 

 43 

 35 



ESTIMATING THE SIZE OF THE BASE- 

 YEAR SHAD RUN 



Total catch and total effort have been deter- 

 mined for each year from 1935 to 1951. To esti- 

 mate the population of shad in each of the 17 

 years, an estimate of total population for a base 

 year was needed. During the 1951 shad fishing 

 season, a tagging program was conducted to de- 

 termine total population, escapement, and fishing 

 rate. Tagging operations began at the mouth of 

 the Connecticut River shortly after the first shad 

 were taken by commercial fishermen there and 

 were continued through most of the season. Two 

 types of sampling gear were used for tagging. 

 The first was a pound net located near the mouth 

 of the river, the second an anchor gill net used 

 in the mouth of the river. The mesh sizes of the 

 tagging gear covered the range of mesh sizes of 

 the nets used by the commercial fishermen. All 

 fish taken in the gill net were tagged, and a high, 

 nearly uniform proportion of the daily pound-net 

 catch was tagged. 



Petersen disk tags, three-eighths inch in di- 

 ameter were inserted high on the backs of the fish, 

 about one-fourth inch behind the anterior insertion 

 of the dorsal fin. The possibility that the tags 

 made the fish more susceptible to capture was 

 considered. It was hypothesized that if the tags 

 caused selectivity, a higher proportion of tagged 

 fish would occur in the catch at the lower end of 

 the fishery, where the shad were first susceptible 

 to capture, than at the locations farther upstream. 

 It developed that the proportion of tagged fish in 

 the catches in the lower reaches of the river was 

 no greater than in those made farther upstream. 

 That tagging did not increase the fish's sus- 

 ceptibility to capture may be due to the fact that 

 the shad is a deep-bodied fish ' and, in the 

 Connecticut River, is generally gilled about the 

 head or gills well forward of the point of inser- 

 tion of the tag. 



Biologists contacted each commercial fisherman 

 once a week to pick up recovered tags and pay 

 the 50-cent reward for each tag returned. A few 

 tags were returned by mail. Of 633 Petersen 

 disk tags used, 349 were recovered in the commer- 

 cial fishery. In addition to the 349 tags actually 

 returned by the fishermen, 10 tags were reported 

 lost or misplaced. Thus the total number of tags 

 accounted for by the commercial fishermen during 

 the 1951 shad fishing season was 359. The pro- 

 portion of returns of fish tagged from gill nets 



