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TROUT HATCHING AT KNARESBOROUGH. 
EDGAR R. WAITE, F.L.S. 
SEVERAL causes have conspired to render the fish so much loved by 
British anglers, viz., the trout, scarce. One of the principal causes. 
is the pollution of the rivers by sewage and waste materials poured 
into them from various manufactories erected on their banks, thus 
rendering trout-producing rivers fewer in number, the remaining 
rivers becoming consequently besieged by anglers and so over-fished. 
Another cause may be found in the ever-increasing custom of 
ignoring the so-called coarser fish for the sake of the higher art of 
throwing the fly, so that the coarser fish are allowed to increase in 
numbers to the detriment of the ova and young fry of the trout; but 
whatever the cause or causes may be, the fact remains that it has 
become necessary, in order to increase the number of trout, to resort 
to artificial means of raising them. The hatchery of the Knares- 
borough Angling Club has been instituted to that end. By the 
kindness of Mr. J. Gavin Brown, the Hon. Secretary, and Mr. Wm. 
Todd, the Bailiff of the Club, I had on the 26th March an opportunity 
of inspecting the process of the operations carried on at the hatchery. 
Before referring particularly to the interior arrangements of the 
hatchery, it will be necessary to imagine that we are accompanying 
the bailiff on his visits during the months of November and 
December to the upper reaches of the Nidd, to which the gravid fish 
have made their way for the purpose of spawning. By means of 
nets the bailiff secures as many of these fish as possible, and with 
gentle pressure causes them to part with their respective reproductive 
elements of spawn and milt into a suitable vessel, afterwards 
replacing the fish into the river. 
Returning to the hatchery, the bailiff transfers the contents of 
this vessel to zinc trays, which are arranged in gradations on both 
Sides of the shed. They are each about three feet long, ten 
inches wide, and four deep, furnished at the outflow end with a 
perforated screen, through which the water passes into the next 
with fine gravel. ‘The water-supply which has to be substituted for 
the natural stream of the river is furnished from two sources. One 
from the substratum of a large adjoining filter-bed, and the other 
from a reservoir of unfiltered water, the object of the latter arrangement 
being to afford a certain amount of organic matter such as would be 
found in the river itself. 
May 1892 
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