OF THE GRIMSBY TRAWL FISHERY. 401 
avoid estuaries altogether,* though both mature and half-grown fish 
may approach the coast where no considerable fresh-water outlet 
exists. The very young stages (having the adult conformation) 
have only been met with on offshore grounds. I am not aware that 
very small haddock ever occur on the Hastern grounds. 
It will be seen from the foregoing remarks that we can generalise 
but little with regard to the distribution of mature and immature 
trawl fish. We can say that the plaice is an estuarine or inshore 
fish in its immature condition, and practically an exclusively 
offshore fish when mature. Soles, turbot, and brill are inshore fish 
and estuarine fish when immature, but to some considerable extent 
are inshore spawners also, i.e. on the Hastern grounds, while the 
plaice is not. Haddock, as far as we are here concerned, may be 
considered as exclusively offshore fish. 
Cuap. 1V.—An Examination, witH Sratistics, or THE DEsrrRucTION 
or Immature F'isu. 
a. By Deep-sea Trawling. 
It appeared to me, on undertaking my inquiries as to the amount of . 
immature fish destroyed in the ordinary course of the trawling in- 
dustry, that this object could best be accomplished by the statistical 
method. Accordingly, during my stay at Grimsby I have endeavoured 
to keep as exact an account as possible of the amount of small fish 
landed there, with as much information as I could obtain about the 
different grounds from which the fish were caught. Owing to 
press of work in connection with my researches on the definition 
of sexual maturity, I was obliged at first to limit the scope of 
my statistics to the plaice, which I soon found to be by far the 
most important species; and during the first year I could only 
afford the time necessary to take the numbers of small fish. During 
the second year | was able to include ail plaice, of whatever size, 
and also to pay attention to the quantity of small haddock and cod- 
ling landed by trawlers, but it has never been possible to attend to the 
total numbers of these two species. The destruction effected by 
shrimp-trawling and various long-shore fisheries did not lend itself to 
statistical inquiry, and for the present my remarks must be under- 
stood to apply only to beam trawling by large vessels, or, as it is 
generally termed, ‘‘ deep-sea trawling.” 
* Large numbers of haddock about 5 inches long were cast up dead on the shores of the 
Humber after the gale of November, 1893. No other kinds of fish were noticed by myself 
on this occasion, the only one on which I have heard of the occurrence of a haddock in the 
estuary under any circumstances, 
NEW SERIES.—VOL. III, NO. V (EXTRA NUMBER). 32 
