The standard procedure for estimat- 

 ing the length composition of haddock 

 landings irom. each statistical area- 

 unit is as follows: 



areas --Subdivisions 5Y North and South 

 and 5Z East and West. A summary of 

 samples of landed haddock is given in 

 table 4. 



(1) Weight of sample is determined 

 from the average weights of fish 

 of each length for the period in- 

 volved (month, season, etc.). 

 Length-weight tables for various 

 ICNAF subdivisions are given by- 

 Clark and Dietsch (1959). 



(2) Weight of the landings is divided 

 by the weight of the sample to ob- 

 tain a factor representing the 

 proportion of the landings which 

 was sampled. 



(3) Number of fish of each length in 

 the sample is then multiplied by 

 the factor obtained to estimate 

 the total length composition for 

 the landings. 



The market categories of large and 

 scrod are handled separately in the 

 above procedure. 



Discarded Portion 



Samples were obtained at sea 

 throughout 1956 aboard Boston large 

 otter trawlers for the purpose of es- 

 timating the composition of the haddock 

 discard. In all, 16 sampling trips were 

 made during which 21,500 haddock 

 were measured. The length estimates 

 for total discard for 1956 in 5Z East 

 and West are summarized in table 3. 



Landed Portion 



Length data for landed haddock were 

 obtained by agents stationed at all 

 nnajor New England ports: Boston, 

 Gloucester, New Bedford, Mass., and 

 Rockland and Portland, Maine. The 

 primary job of these agents was to 

 interview trawler captains and sannple 

 catches of species taken in the otter 

 trawl fishery. The composition of the 

 trawler fleets and their fishing prac- 

 tices and areas of operation varied 

 greatly from port to port, but the 

 sampling coverage was sufficient to 

 provide an adequate representation of 

 the landings from each of our four 



Length connpositions for 5Z are given 

 in tables 5 to 17 for East and West 

 sections by months and in sun-imary for 

 the haddock year. The data are given 

 by month to serve the purposes of 

 evaluation of the ICNAF mesh regula- 

 tion. The figures given in these and the 

 following tables on length and age 

 composition of the landings are esti- 

 nnated total numbers of haddock of each 

 length removed for human consumption 

 by the entire fishery in the 1956 had- 

 dock year. 



Length compositions for 5Y are given 

 in tables 18 to 22 for North and South 

 sections by seasons and in sunnmary 

 for the haddock year. The 5Y data are 

 summarized by seasons to conserve 

 space because a detailed monthly 

 breakdown is not required as it is for 

 subarea 5Z which supports a fishery 

 that is much larger and has been under 

 intensive study since 1931 and under 

 regulation since 1953. 



Too few samples were obtained from 

 the industrial fishery to permit deriving 

 length compositions of these landings. 



AGE COMPOSITION OF CATCH 



Haddock ages listed herein have been 

 estimated from examination of scales 

 taken from an area below the lateral 

 line behind the second anal fin. The 

 technique adopted is the usual one used 

 in reading scales--the narrow bands of 

 circuli which are formed during each 

 winter are counted to estinnate the age 

 of the fish. In conformance with past 

 studies, February 1 is used as the 

 standard birth date for all haddock. All 

 fish older than 8 years are combined 

 into the single category 9+. The methods 

 used have been shown to provide re- 

 liable estimates of age for haddock at 

 least through age 5. There is some 

 evidence that the estimates for older 

 fish, particularly those 8 years and 

 older, may be less reliable but these 

 older fish fornn a negligible part of the 



