of the Fishery Board for Scotland. 
197 
all Hat-fish under, say, 8 inches, many immature forms would not be 
caught (vide Table III. p. 163), and this considered alone would be an 
advantage. The size of mesh necessary could be determined by a few 
experiments. It is questionable, however, if the benefit accruing from 
the adoption of such a mesh would not be more than counter-balanced by 
certain disadvantages. The mesh would capture the smallest adults of 
most flat-fishes, but it would allow many adults of the comparatively 
valueless flat-fishes, as the common dab, long rough dab, &c, to escape. 
These fishes are abundant on the Scottish coast, and it is shown by Mr 
Ramsay Smith in the Report on the Food of Fishes (p. 230) that they 
live to a large extent on the same food as soles, plaice, and haddock. 
Would it be, on the whole, beneficial to put a premium on the multi- 
plication of these fishes — which occupy ground and consume food capable 
of rearing multitudes of other more valuable fishes in order to preserve from 
capture a considerable proportion of immature plaice and soles, and a 
moderate proportion of turbot and brill 1 It is a subject for further inquiry. 
It is, I think, obvious that limitation of the size of the mesh will not 
alone solve the problem. 
Another measure advocated is, as in shrimp-trawling, while allowing the 
capture of immature individuals, to pick them out and return them to the 
sea, when the net is hauled. As trawling is at present carried on, it is 
doubtful if such procedure would be of much advantage. When a net 
is down five, six, or seven hours the probability is that at all events most 
of the immature flat-fish in it are either dead before they are brought to 
deck, or are so much impaired in vitality that they will die before they 
can be picked out or after they are returned to the sea. Our knowledge 
on this point is not however very exact. Professor M'Intosh* states that, 
during the experiments in connection with the Trawling Commission of 
1884, the turbot were 'as a rule active when freed from the trawl' 
and that 'all the brill and soles were alive and in fine condition.' He 
describes the sole as 'one of the most tenacious amongst flat-fishes.' 
He also points out that no fish was so hardy as the plaice. From an 
examination of the records made by Professor M'Intosh, it appears that 
when the net was hauled all the turbot, brill, and soles were alive. 
Turbot, brill, and plaice were living after the net had been down as long 
as seven hours and twenty minutes on a sandy bottom; all the soles 
when the net had been down for five hours even on a muddy bottom. 
Some plaice were dead after the net was down for four hours on a 
muddy bottom. Dabs succumbed much more rapidly. The vitality of 
immature fish appeared to be much less — but turbot, brill, and soles are 
not included in this class. No turbot, brill, or soles were caught during 
the experiment made on board the 'Garland' (vide p. 183), but some of 
the plaice died before their condition could be recorded ; and it is doubtful 
how many would have lived if they had been returned to the sea. In this 
connection the routine operations on board a trawler must be borne in 
mind. 
It appears to me very necessary, at all events, that further experiments 
should be made before it can be assumed that even moderately sized 
immature turbot, brill, and soles will live when returned to the sea, after 
the net has been down a few hours. It would be a mere waste to return 
such fish to the sea unless it were certain they would live. 
From what I have stated in this Report as to the distribution, capture, 
and destruction of immature fish, and from general considerations, I think 
that certain principles may be laid down, and certain recommendations 
made. 
* Op. cit., p. 358. 
