of the Fishery Board for Scotland. 
195 
regulative measure is proposed, is the proportional abundance on the 
shrimping grounds of the young of the various kinds of flat-fishes. 
Scientific reasons are given below which render it doubtful whether it is 
wise to attempt to preserve the young of the almost valueless dabs from 
destruction ; but there can be no question at all as to the wisdom of 
preserving the young of the more valuable flat-fish — turbot, soles, brill, 
plaice, &c. It has been shown where young plaice and young soles 
abound, possibly young turbot and brill are present in large numbers in 
many similar localities, although I do not think the scientific evidence in 
favour of this view is as yet conclusive. It is a subject for inquiry, for 
the flat-fish nurseries at different parts of the coast differ in the proportion 
of the fish composing them. It is very desirable that a careful scientific 
inquiry should be made into the capture and destruction of young fish 
by shrimp-nets, seines, weirs, and fixed nets around the shores. 
Beam-ir aiding. 
The capture of immature flat-fish by beam-trawlers stands on a different 
footing. In dealing with this question I shall consider (1) the actual 
capture of immature flat-fish by beam-trawling ; (2) whether and to what 
extent this is detrimental, and (3) how it may be avoided. It has been 
shown by the. investigations detailed in this paper that trawlers capture 
large quantities of immature flat-fish ; although almost certainly not so 
many very small ones as do shrimp fishers. The trawlers themselves 
admit that they kill large quantities of young fish ; and they desire to 
avoid it. One trawler has stated that he has seen 1000 vessels in the 
North Sea getting at the rate of two or three tons of immature fish, night 
after night for two or three weeks. * No doubt this picture is largely 
exaggerated. The question as to the extent to which the capture of 
immature fish is prejudicial, is difficult and complex. I have shown 
(p. 163) that a plaice under twelve inches, a turbot under about eighteen 
inches, a haddock under ten inches, and a cod under twenty inches are 
immature, and have not performed the function of reproduction. That is 
the biological statement of the case. But beyond that there is the 
economic side which must necessarily be the final appeal ; for the object 
is how to obtain year after year the largest possible harvest of food from 
the sea without endangering future supplies. There is no question that, 
a large number of immature fish (such as those named) are eminently 
saleable and wholesome, and in point of fact they now furnish an important 
article of diet. The great problem is to determine for each kind of fish 
the size which may be allowed to be caught and the size which should not. 
In the case of round-fish there is little difficulty ; they are abundant, the 
very young specimens escape capture by hook and by trawl, and the 
supplies are not falling off. In the case of the more valuable flat-fish one 
principle can be laid down; that the destruction of young individuals which 
are unsaleable, or so small from the economic point of view as to be of 
comparatively little value, should be prevented in every way possible. 
No one will dissent from that. But is it expedient to recommend that, 
say, all turbot under about eighteen inches, brill under about sixteen 
inches, and plaice under twelve inches, should be preserved? It must 
be remembered that an immature individual approaching sexual maturity 
is of much more value to the species than several which are less developed 
Thus more harm will probably accrue by the destruction of one turbot 
at sixteen or seventeen inches than by the destruction of a dozen at 
* Nat. Sea Fisheries Protect. Assoc., Report of Proceedings at the Conference of 
Representatives of the Sea Fishing Industry, p. 37, 1889. 
