_Salmon Fishery in the Thames_ (Vol. iv., p. 87.).--Those of your
readers who know that I am connected with Billingsgate market would look
to me for the reply to R. J. R.'s Query. I must therefore inform them
that only thirty or forty years back salmon were taken in rather large
quantities in the Thames; but since the introduction of steam-boats and
the increase of traffic, the fish have gradually, I might say suddenly,
disappeared, for during the last twenty years very few salmon indeed
have been taken: those that found their way to market have realised high
prices; not that Thames salmon was ever esteemed for its flavour, but
only for its extreme rarity of late years.
The hindrance to salmon taking the Thames is the steam-boat and other
traffic, which, agitating the water, frightens them (they being a very
timid fish), and stirs up the mud, which chokes them; for there is no
doubt that ever after a salmon enters a river, it lives by suction. It
is possible that one or two salmon a season even make up our river now,
for becoming frightened, and rushing on having back and head nearly out
of water, and the tide with them, they would get a long way in a night,
and possible reach clear water above bridge with life, but in a very
weak state. I believe that, under the most favourable circumstances,
salmon would not again frequent the Thames in any large quantities, it
being too southern; and there is no doubt but that the fish have been
fast decreasing of late years, for some of the best rivers in the north
are now without salmon.