thai of haddock in other regiOub, especially to that of the North Sea. The observa- 

 tion that older fish generally seek deeper water and appear to migrate more than 

 younger fish is in agreement with fir.dings in other areas (Thompson 1943). 



Abundance and Age Composition as Related to Bottom Type 



" During Albatross III c ruises more than 250 bottom samples were obtained by 

 use of "scoop-fish" bottom sampler attached to the nose of a bathythermograph. 

 This sampler worked successfully, obtaining approximately a 50 -gram sample over 

 mud,, sand, and gravel bottoms, while over harder bottoms only chips were obtained. 

 The bottom samples thus taken were classified according to the four size categories 

 given m the Hydrographic Manual (Adams 1942). 



When these data were plotted and lines of demarcation drawn, it became 

 apparent that due to the insufficient number of samples in certain areas and the in- 

 ability of the gear used to obtain a reliable sample of particles larger than 6.0 mm. 

 that the following consolidation of the data was advisable; 



Sediment Description 



Sand Sand and stony sediments with particle 



diameters greater than 0.1 mm. 



Mud Mud and sand-mud sediments with 



particle diameters mostly less than 0. 1 mm. 



This consolidation was verified by the fact that the distribution of haddock was 

 similar over sand and stony bottoms and over mud and sand-mud bottoms . A chart 

 (fig. 13) was prepared according to this classification of Albatross lU samples and 

 to data given m Coast and Geodetic Survey Charts 1106A and 1107A. 



Summer 



Figure 14 and table A-3 show the total and the relative abundance of the differ- 

 ent ages of haddock over sand and mud for the years 1948, 1949, 1950, and the 1949- 

 1950 means. 5/ The total catch per tow was consistently greater over sand than over 

 mud bottoms and this greater abundance was in large part due to the greater numbers 

 of younger fish. 



In table 14 the catch per tow and wei^t per tow data by bottom type is grouped 

 into unmarketable haddock, scrod, large haddock, and total marketable haddock, as 

 was done with the catch by depth zones. 



5/ The catch per tow by bottom type for the individual subareas are tabulated in 

 tables A-4, A-5, A-6, A-7, A-8, and A -9 in the appendix. 



34 



