In New England the complaints reached a crescendo soon 

 after the introduction of the otter trawl — an introduction 

 made by Captain Collins, Chairman of the U.S. Fish Commis- 

 sion, in 1903. By 1912 the first American steam trawler, Spray, 

 and five sister ships, Foam, Ripple, Crest, Surf, and Swell, 

 were routinely fishing Georges Bank. To address the com- 

 plaints, David Belding, a biologist for the Massachusetts Com- 

 mission on Fisheries and Game, conducted an investigation on 

 the effects of otter trawling by making a trip on the FV Foam 

 in that year (Belding 1916). During Belding's trip the vessel 

 discarded as undersized about 25% of the haddock and 14170 

 of the Atlantic cod caught. He assumed 100°7o mortality for 

 these discarded fish. The cod end mesh size was probably 

 smaller than 3 in. 



Belding's work was soon followed by that of Alexander et 

 al. (1915) as described in the introduction of this report. From 

 data collected on 61 trips, they found that by weight "... 40 

 per cent of the cod and 38 per cent of the haddock taken by the 

 otter trawlers from June to December were fish too small to 

 market. From January to May but 3 per cent of the cod and 1 1 

 per cent of the haddock were unmarketable on account of 

 their size." By numbers, for haddock, this amounted to 77 and 

 40%, respectively (Herrington 1935). Their observers reported 

 practically all of these discarded fish as dead when thrown over 

 the side. The cod end mesh size was about 2.5 in. 



Herrington's work in the 1930-31 period, when small had- 

 dock were unusually abundant, indicated discards of undersiz- 

 ed fish two to three times larger than marketable haddock 

 (Herrington 1932). He went on to say that the commercial cap- 

 tains were concerned enough about this to make an agreement 

 among themselves to avoid grounds where small fish 

 predominated. However, the small fish were everywhere, mak- 

 ing the agreement ineffective. In that 1-yr period, 1930-31, 

 about 63 million baby haddock were destroyed, "...about 

 equal to the number of haddock in a commercial catch of 

 200,000,000 pounds" (Herrington 1936). Again, this destruc- 

 tion varied by season, area fished, and yearly. 



Premetz (1953) reported that for the 1947-51 period annual 

 discards of undersized haddock were over 4.5 million lb, 

 representing over 6% of the catch. The greatest part of the 

 destruction occurred from June to November. His data further 

 show that the overlap in culling between discards and fish re- 

 tained for market ranged from 11 to 19 in (0.5 to 2.3 lb) and 



was usually a function of the size of the catches. The majority 

 of the culling occurred between 13 and 15 in (33 and 38 cm). 



From fishermen's reports, the discard of 1975 year-class 

 haddock during 1977 was very high. It may have been of the 

 same order of magnitude as that reported for the 1930-31 

 period mentioned above. Even though there was a mesh-size 

 regulation in effect, reports indicate that many fishermen 

 geared down, either using a smaller mesh or liner, to catch the 

 abundant small haddock that are sold as "scrod." 



Haddock and Atlantic cod are not the only fish discarded. 

 Lux (1968) reported yellowtail flounder discards of 50% of the 

 catch by weight. This was using mesh sizes of about 114 mm 

 and a cull point of about 35 cm. The survival of discarded 

 yellowtail was estimated by Lux to be about 25% The average 

 discards and landings for 1963-66 averaged about 11,000 and 

 33,000 t, respectively (Hennemuth and Lux 1970). 



A summary of the results, in regard to discards, of the 

 catches made during the series of experiments reported in the 

 previous sections of this paper is contained in Table 28. For 

 Atlantic cod, haddock, and winter flounder, there was a 

 reduction of discards and an increase in landings by the larger 

 mesh. For yellowtail flounder there was a reduction of discards 

 and of landings. In reviewing this data, the question arises that 

 if this overall increase in catch and decrease in discards is in 

 fact true, why have not the fishermen optimized their opera- 

 tion by going to a larger mesh (5 in or greater)? Several 

 hypotheses are offered. 



1) Evolutionary development (gear). The otter trawl has on- 

 ly been fished in New England for 75 yr. During this period 

 there has been an increase in mesh size and many "highliner" 

 captains do use mesh sizes over 5 in. Evolutionary develop- 

 ment is a long process and just may not be complete in regard 

 to optimizing mesh size. 



2) Economics. The catch of smaller species of fish, i.e., 

 whiting, may offset the loss of catch of larger groundfish caus- 

 ed by reduced trawl efficiency. The inshore fleet may be a 

 good example of this. 



3) Natural cycle variations. Every so often a good year class 

 of Atlantic cod or haddock comes along. The fishermen will 

 fish these schools when only a small portion of the fish have 

 reached market size and thus will use a mesh size that would 

 retain 100% of the scrod, roughly a 4-in mesh. Anyone using a 

 larger mesh will most likely catch fewer marketable fish. 



Table 28. — Discard summary for New England mesh experiments using only uncovered cod-end 



data. 





Discard 



105 mm 



cod ends 



135 mm 



cod ends 



Large mesh 



Large mesh 





size 

 (mm) 



% discard 



% discard 



% discard 

 reduction 



landings 



Species 



No. 



Kg 



No. 



Kg 



% change 



Atlantic cod 



<42 



28.3 



6.9 



3.2 



0.6 



93 



+ 35 





<S2 



47.3 



15.5 



11.6 



3.4 



78 



+ 44 



Haddock 



<42 



4.5 



1.9 



0.6 



0.3 



84 



+ 25 





<52 



29.5 



19.4 



15.3 



10.4 



46 



+ 36 



Yellowtail 



<30 



36.9 



13.6 



10.2 



3.4 



75 



-25 



flounder 



<36 



73.3 



50.1 



54.8 



37.2 



26 



-16 



Winter 



<30 



51.8 



27.5 



16.6 



7.4 



73 



+ 37 



flounder 



<J6 



74.1 



48.4 



56.6 



35.6 



26 



+ 25 



18 



