366 Part III. — Twentieth Annual Report 



ti'awl or the small meshed net, and not a, single larger dab than the one 

 measuring 80 mm. was found.* The hauls taken on this and the 

 following day in Aberdeen Bay were extraordinarily poor, so that the 

 fishing was abandoned by the trawler as unremunerative. A four-hours' 

 drag yielded only 23 marketable and 181 uimiarketable (small) fishes, 

 and in the total of 204 there -were only eight flat fish, six plaice and 

 two dabs. Another haul for four hours yielded 247 fishes, including 

 only five flat fishes, viz., four plaice and one brill, no dabs at all being 

 taken. Haddocks were also extremely scarce, only three being procured 

 in the two diugs of eight hours, the catches being mostly composed of 

 small whitings, large cod, and starry rays. The weather had been very 

 stormy previously, and the fish had probably moved oiit into deeper 

 water away from the commotion at the bottom near the shore. This 

 must have been the case with the haddocks, although many fishermen 

 think the flat fishes bury themselves in the sand. But whatever the 

 cause, the only dabs caught were those mentioned, and thus the absence 

 of a dvie proportion of the larger members of the first series might be 

 explained by the fact that they were able to move ofi' with the older 

 dabs. Dabs are usually extremly abundant in Aberdeen Bay, and are 

 frequently taken in thousands. 



Moreover, the upper limit of the group — the maxinuim size of 

 individuals belonging to it — was considerably higher in previous 

 months, e.g., on 31st October 89 mm., the next largest (or the smallest 

 member of the older series) being 100 mm; 17th-21st December the 

 largest was 88 mm., and the smallest of the next series 90 mm.jt 18th 

 October, 1901, 82 mm., the next largest being 94 mm., and on 29th 

 November the limits were 92 and 106. Moreover, a study of the "Scm. 

 curves also indicates the absence of a due proportion of the larger 

 members of the series, because while the arithmetical average is47*8mm., 

 and the maximum ordinate of the curves between 46 and 47, the median 

 oi^dinate on the base lies over 5"2 cm. 



Dr. Kyle % states that a dab measuring. 17 '5 mm. was taken in the 

 Forth on 19th January, and one on 4th March measuring 20 mm. It 

 is possible, therefore, if the dates are accurate, that the true lower limit 

 of the dabs taken in Aberdeen Bay is really lower than 28 mm. I am, 

 however, inclined to think that those referred to by Dr. Kyle are 

 exceptional, and that the lower limit is not much less than what is 

 indicated by the measurements in this case, but may be put at 25 mm. 

 The higher limit, judging from other hauls, may be placed at 88 mm., 

 and on this basis the more correct mean size of the group would be 

 56*5 mm., showing an increase of 8'7 mm. over the mean size computed 

 from the actual measurements. 



There were some other hauls in which very small dabs were taken. 

 Thus a haul with the shrimp trawl in 12 fathoms of water, outside the 

 Suters of Cromarty, on 11th December 1901, yielded seventeen dabs of 

 this series, ranging from 23 to 66 mm., the average size being 49'5 mm., 

 or \\^ inches, and on 10th January, in 6|-7 fathoms, within the 

 Cromarty Firth, three were taken measuring 41, 42, and 52 mm., and 

 with an average size of 45*0 mm., or 1| inches. The numbers in these 

 cases are small. 



* The '5 cm. grouping of the small dabs is as follows : — 



2-5 — 3 — .3-.''i — 4 — 4-5 — 5 — 5-5 — 6 — 6-5 — 7 — 7-5 — 8 

 3 17 28 33 44 30 30 16 6 3 1 



f The mm. groups are as follows :— 



75 76 77 78 79 SO 81 82 83 84 85 86 87 88 89 90 

 27 20 17 10 5 6 5 5 3 3 2 2 ] 1-1 



± Lov. fit. 



