of the Fishery Board for Scotland. 87 



each of a period of successive years, to allow conclusions to be drawn from 

 statistics which referred to the whole area respecting change in its pro- 

 ductiveness ; and that is a condition most improbable. 



With regard to this question of the place of fishing, there arc two 

 points to be considered ; first, the areas which should be chosen for com- 

 parison, and, second, the means by which the information may be 

 acquired. 



With regard to the first, by far the most important factor determining 

 the proportional distribution of the various species of fish is the depth of 

 water. It is not the distance from the shore, but the depth. The fish 

 obtained, for example, in a small depression of 50-75 fathoms, a few 

 miles from Aberdeen, where I have carried on trawling experiments, 

 resemble in kind and proportional abundance those caught in water of 

 somewhat similar depth south east of the Shetlands. A haul made in 30 

 or 40 fathoms in the middle of the sea more closely resembles one got 

 near shore in about the same depth. A subsidiary cause of variation is 

 the geographical position ; the black or common sole, for instance, is 

 extremely rare on the east coast of Scotland, even where the depth is 

 suitable. 



Such being the case, the most natural areas would be those representa- 

 tive of the deptli of the water, and in the North Sea the twenty fathom, 

 thirty fathom, fifty fathom, and one hundred fathom contour lines might 

 be selected. The actual areas within these lines are, however, too large 

 for the purpose, for although the range of migration of the fishes, or the 

 correlation of one part with another, is not sufficiently well known, there 

 is little or no doubt tliat the inclusion of such distant parts as the Fisher 

 Bank and the sea ofl: the coast of Northumberland in the same area would 

 be Avrong. Extent as well as de])th must be taken into account. In 

 dealing with the information at Aberdeen, I selected as most convenient 

 areas of 1° latitude and 2' longitude, which in most cases would probably 

 answer well. 



The precise area to be selected for exhibiting the results is not, how- 

 ever, of much immediate importance. The chief thing is to determine 

 and record the place of fi.shing. In ascertaining the place of fishing it 

 appears to be sometimes supposed that it would be necessary, first of all, 

 to fix the position and extent of certain areas, and to ask the fisherman 

 to say which area he had been fishing in ; or to ascertain from him the 

 latitude and longitude of the place, or to discover if he was fishing north 

 or south, east or west of a given line. But this is unnecessary, and 

 would probably be confusing. Every fisherman knows very well where 

 he is fishing. If near the coast he has landmarks, or it may be compass 

 and his lead. If at a distance from the coast he steers a course by his 

 compass, runs a certain distance as determined by his log. ascertains the 

 depth and the nature of the bottom with the sounding lead, and then 

 shoots his gear. From Aberdeen, for example, when fishing on the 

 north-eastern grounds, the practice is for the trawler to run up the coast 

 to Buchan Ness and then to shape his course to where he has decided to 

 go, measuring the distance from there ; if he is going east or south-east 

 the course is steered and the distance measured from Girdleness on 

 leaving port. All that requires to be asked is — " What course did you 

 steer?" The answer may be, "North-east by east, easterly, from Buchan 

 Ness." " How far did you run r' " 120 miles." "What depth r' " 70 

 fathoms." The place of fishing can then be marked on a chart, similar 

 to the one used by the trawler. Obviously, for the purpose of subse- 

 quently exhibiting the results of a large number of observations, any area 

 on the chart that is most suitable for the purpose may be selected. It 



