8 Fishery Board for Scotland. 
Horizontal Hauls for half-hour 
Vertical with 1 mm. ch. el. net at 
PostItTIon. 
Haul. 
Surface, | Mid-water.| Bottom. 
Off Lybster, . . : ; 108 2 955 784 
Off Helmsdale, : ; f 33 12 611 466 
South of Smith’s Bank, less 
than 50 fms., : : 30 86 213 296 
Dornoch Firth, . : ; 14 63 251 102 
E. of 'Tarbet Ness, . : 4 43 16 146 47 
Off Burghead, . : : : 17 18 (3 189 
Off Lossiemouth, . : : 9 17 180 464 
Off Portknockie, . : , 11 72 220 688 
Off Troup Head, . : 16 AT 235 219 
Kinnaid Deep, : : ; 0 13 40 58 
58° 00' N..to 58° 10'.N., 2 3 32 21 
iPvDO / We to. 2°10 i W.-, } 4 23 50 150 
These figures are in marked contrast to those of the area already 
considered. As in the previous case, they are the averaged results 
of the hauls taken, and the observations were all made on the same 
plan. The numbers in the different columns clearly indicate a 
significant decrease in the frequency from the one area to the other. 
Further, the number in the largest individual haul taken towards 
the end of the month do not even approach those (already quoted) 
for a single haul near Dunnet Head in the early part of the month. 
The evidence is conclusive that the larve of sand-eels at this time of 
the year in the Moray Firth are much less numerous than in the 
adjacent area to the north. 
Depth and character of the bottom are two factors which have a 
powerful influence in determining the spawning areas of a species 
with demersal eggs, such as the sand-eel. Now, about half the area 
of the Moray Firth has a depth of less than 30 fathoms, and the 30 
fathom contour line runs throughout its whole length almost 
parallel to the coast. The area between the coast and this line is 
largely composed of sand, and on the whole it does not show any 
striking want of uniformity in the frequency of occurrence of larval 
sand-eel, as may be seen from a consideration of the table of figures 
and the accompanying chart. On the south side of the Moray Firth 
beyond a depth of 30 fathoms there runs eastwards a gradually 
deepening valley, where the bottom deposits are of a different 
character. Here mud prevails. In the centre of this valley, from 
Burghead eastwards, the percentage of mud increases, and towards 
its eastern limit mud is predominant. These conditions are 
continued even beyond this area, and culminate at the Fladen 
grounds, where at a depth of over 80 fathoms the bottom is of very 
fine mud. ‘To the north of the Moray Firth valley the deposits grade 
into the sandy grounds which stretch from the east of Caithness to 
beyond Fair Isle. Over this valley there is a marked decrease in 
the number of sand-eels, and the decrease is even more marked 
when we contrast a haul in this area with one at a corresponding 
