225 
sexes the total number of mature fish can be further cal- 
culated. Such determinations made from year to year 
would obviously give the fluctuation of the adult Plaice 
population. 
Of all the Pleuronectid food fishes the Plaice is the 
most important by reason of its relatively great abundance 
and on that account when the probability of the decline of 
the fishery became evident it was the object of much solici- 
tude on the part of the fisheries authorities, and many 
remedial measures have been proposed. In this country 
the continual destruction of immature fish has been the 
most obvious danger to the fishery, and the remedies have 
all been directed to the minimising of this evil. The idea 
underlying the remedies suggested has been to allow as 
many fishes as possible the chance of spawning at least 
once in their lifetime. This destruction of immature fish 
takes place in every form of fishery. Practically all the 
fish captured in inshore fishing, whether by trawl or stake 
net, are immature. Even in the deep sea Grimsby fishing 
more than half the fish landed are immature. In 1894* 
of the Plaice landed at that port 7 millions were mature 
and 9 millions immature. Of the same quantity 9} 
millions were over 15in. in length and 6} millions under. 
At first sight therefore it might appear that the imposition 
of a size limit below which it would be illegal to land the 
fish would be an effectual remedy. If based on the size at 
which sexual maturity first occurs this limit would vary 
for different localities. It is obvious, however, that such 
a regulation is impracticable, since the Plaice becomes a 
marketable fish long before it becomes sexually mature. 
The imposition of such a limit would close the inshore 
grounds against plaice fishing altogether. 
Other size limits have, however, been proposed, and 
* Holt—loc, cit., p. 410. 
