p. magellamcus , found in the haddock's diet 

 were the soft body parts with the notable ex- 

 ception of the adductor muscle. There is 

 heavy fishing for sea scallops in riie North- 

 east Peak area . And on board ship the ad- 

 ductor muscle IS removed and the remainder 

 thrown overboard. Apparently it was the re- 

 mains of scallops discarded by scallop 

 fishermen that were eaten by the haddock. 



Fish constituted 2 . 6 percent of the diet 

 and were present in 4 percent of the speci- 

 mens . This quantity of fish in the diet is 

 slightly greater than the average for Georges 

 Bank as a whole . 



Southeast Part 



A large area in the south central portion 

 of Georges Bank has been designated the 

 Southeast Part. Most of this area lies be- 

 tween the 30 and 50 fathom isobaths. Sand 

 is the major substrate constituent with admix- 

 tures of shell fragments and gravel from 

 place to place . The food habits of haddock in 

 this portion of Georges Bank were determined 

 by stomach analysis of 532 specimens from 

 19 collection stations . Mean body length of 

 these specimens was 39 centimeters; ex- 

 tremes were 16 and 75 centimeters. Their 

 average stomach content volume was 2 . 41 

 cubic centimeters. 



Crustaceans were the major foods of pad- 

 dock in this area . Mollusks and annelids 

 were of secondary importance and echino- 

 derms, fish, and miscellaneous groups were 

 of minor valu6 . The number, frequency, 

 and volume of each group of stomach contents 

 are recorded m table 7 . 



Amphipods and decapods were the pri- 

 mary crustacean forms preyed upon by 

 haddock in this area. The amphipods pro- 

 vided 34.0 percent of the total stomach 

 content volume and the decapods 5.3 per- 

 cent . Considering all food groups, the 

 ampkipods ranked first m number and fre- 



quency of occurrence as well as in volume . 

 One particular species of amphipod that 

 occurred in enormous numbers was Byblis 

 gaimardii (Kr5yer). Other species frequent- 

 ly encountered were: Monoculodes edwardsi 

 Holmes, Leptocheirus pmguis Stimpson, and 

 Unciola irrorata Say . 



Mollusks commonly eaten by haddock in 

 this part of Georges Bank were: Colus 

 pygamaeus Gould, Yoldia thraciaeformis 

 Storer, Y, sapotilla Gould, and Solemy velum 

 Say (and/or S . borealis) . Very few living 

 gastropods were eaten by haddock . In nearly 

 all instances the gastropod shells were in- 

 habited by hermit crabs . Invariably all shell - 

 bearing mollusks found in haddock stomachs 

 were of small size Most specimens were 

 less than 5 and 15 millimeters in height and 

 length, respectively. 



The sand dollar^ Echinarachnius parma 

 Lamark, was the predominant echinoderm 

 in the food of haddock from this area . This 

 species was most abundant in the samples 

 from the western end of the Southeast Part. 

 Again, only the small (3 - 20 millimeters in 

 diameter) specimens were taJcen by haddock . 

 Large specimens or pieces of large speci- 

 mens were not observed m the stomach 

 contents . 



EVALUATION OF FOODS 



Three criteria were employed for deter - 

 mimng the importance of the various food 

 items that were found in stomachs of haddock , 

 They were as follows: (1) Percentage volume ■ 

 the volume calculated from the total stomach 

 contents of all haddock representing the par- 

 ticular area or season under discussion, and 

 expressed as a percentage . (2) Frequency of 

 occurrence - determined by counting the num- 

 ber of stomachs in which the item occurred 

 in the area or season . (3) Number of organ - 

 isms - a summation of the number of speci- 

 mens of each item found in the stomachs-. 

 In the calculation of averages and percentages 



16 



