AN ANGLER'S NOTES ON DAGENHAM LAKE. 147
Pike or Jack (Esox lucius).—All sizes, from quite small up to
twelve and fourteen pounds each.
Eel, Common Sharp-nosed (Anguilla aculirostris).
Eel, Snig (A. mediorostris).
Trout are said to have been taken, but I have never seen any;
and Flounders have probably been only accidental visitors.
This fishery has much deteriorated during the last ten years ; the
fishes now taken being fewer in number and much smaller in size
than of old. The following circumstances have doubtless helped to
cause this.
Some tons of fishes were poisoned a few years since, by the acci-
dental admission into the lake, through a broken sluice, of an immense
quantity of floating slime and other matters from the deodorizing
works at the sewage outfall on the opposite bank of the Thames.
The direct flow of water from the Beam river (which at times
caused a perceptible current through the lake) has been almost totally
stopped, the old communication being choked up.
The smoke from steamships on the Thames, when a southerly
wind is blowing, passes over the lake, and much soot falls upon the
water. This is very injurious.
A large ditch communicating with a pool on the north side of the
lake, and which used to be the great retreat for the larger fishes at
spawning time, has been filled up. The new roadway now passes over
it, and the communication is stopped.
The fishery would, I feel sure, soon improve if a new opening
between this old spawning pool and the lake were cut, and the old
direct flow from the Beam river renewed.
There has been much controversy on the subject of the sense of
hearing in fishes ; its existence being denied by some on account of
the absence of auricular apertures, while asserted by others from
practical experiment. An experience I have many times had at
Dagenham may, to some extent, perhaps, be new or interesting, and
may help to throw some light upon this subject.
I have seen thousands of fishes leaping out of the water at the
same instant, over all the surface of the lake, as far as my sight could
take cognisance. I knew that it was common to see shoals of fish
leap out when suddenly attacked by a pike, but at such times the
space covered would never exceed a few square yards, and that this
very general appearance of fright must be from some very different
cause.