|If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.|
||Thread Tools||Display Modes|
Salmon in London
One last great effort is to be made to bring back the Thames salmon, the
fish that disappeared for a century and a half.
More than two decades of work by fisheries scientists has failed to induce
salmon to breed again in a river that once contained them by the thousand,
and doubts have arisen over whether breeding is possible.
Despite much research, annual stocking with thousands of young fish since
1979, and a £4m programme of building fish passes, no case has yet been
found of Salmo salar returning to the Thames and spawning successfully.
But after a reassessment of the long-running Thames Salmon Rehabilitation
Scheme this year, and consultation with interested parties, the Environment
Agency is preparing a five-year Salmon Action Plan for the Thames that will,
in effect, be the last chance to bring back the king of fish as a natural
inhabitant of the nation's principal river.
Once it was almost too plentiful - apprentices in medieval London protested
that their diet was over-reliant on salmon - but the growing pollution and
filth dumped in the river as the industrial revolution proceeded in the
early 19th century built up a chemical barrier to any fish trying to swim up
from the sea.
The last salmon seen in the Thames until recent years was found in 1834. In
the 1950s and 1960s huge strides were made in cleaning up the two enormous
sewage outlets, at Crossness and Beckton in the Thames estuary, which were
pouring thousands of gallons of untreated filth into the river every day.
The water quality improved dramatically and, on 12 November 1974, the
amazing happened - a 9lb (4kg) female salmon was found in the intake screens
of West Thurrock power station. It was so surprising that it was sent to the
British Museum for positive identification.
The dream of bringing salmon back to the Thames started then, and the
rehabilitation scheme began in earnest five years later, with thousands of
young fish - tiny fry, three-inch-long parr and six-inch-long smolts -
stocked at various points of the river each year.
The scheme has had one undoubted triumph. It showed that the river was clean
enough for salmon to swim through on their journey down to the sea and the
journey back up to breed. Good numbers of returning fish were trapped every
year, reaching a peak in 1993 when 338 were taken.
But breeding did not take place, mainly because the way to the spawning
streams in the higher reaches of the river was blocked by weirs. An
ambitious project began in 1984 to build fish passes in 39 weirs between
Teddington, where the tidal Thames ends, and the upper reaches of a
tributary, the river Kennet.
The Kennet is a crystal-clear chalk stream that flows through Berkshire and
enters the river at Reading, and its upper reaches, in particular a stretch
between Newbury and Hungerford known as the Wilderness Water, have been
identified as the best potential salmon spawning area in the whole of the
Thames catchment, because of the gravelly stream beds in which the fish can
scoop out their egg-laying sites, or redds.
The last fish pass was completed in 2001, after a total expenditure of about
£4m. However, although stocking has concentrated on the Upper Kennet since
1994, no fish has yet been found returning and spawning successfully, and
numbers of returning fish have dropped very low. In 2003, only 15 fish have
"There's no doubt that's a very disappointing return," said Darryl
Clifton-Dey, the Environment Agency official in charge of the scheme. He
blames the poor number on the difficulties the young fish have to negotiate
on their long journey to the sea - everything from cormorants and pike to
water intakes - and the hotter, drier weather of recent years and the lack
of rain. "Salmon seem to need a flush of water to encourage them to swim
back up a river," he said.
But the agency has now drawn up a plan for a last determined effort to get
Thames salmon to use the Kennet as their spawning stream, and breed
naturally, with a target of 250 local-bred fish returning every year. It
will last for five years and cost about £250,000 a year - and the agency
will welcome partners.
"We definitely think it is worth doing," Mr Clifton-Dey said. "When I was
growing up in south London, people thought of the Thames as just a ****ty
ditch, and to know that salmon were back in it would be a marvellous thing.
It is the fish that people associate with a clean river - to have salmon
makes a river special.
"To have salmon swimming up the Thames to breed, past the Millennium Wheel
and the Houses of Parliament and Windsor Castle, is something of which
everyone living in London would be very proud."
|Thread||Thread Starter||Forum||Replies||Last Post|
|valley (river) king salmon swap||Steve Sullivan||Fly Fishing||3||March 27th, 2004 12:15 AM|
|Talk about a slow moving Salmon||Marshall Krasser||Fly Fishing||1||January 25th, 2004 07:13 PM|
|Picture this....||Guyz-N-Flyz||Fly Fishing||73||January 14th, 2004 04:14 PM|
|First salmon||haresear||Fly Fishing||5||November 5th, 2003 06:21 PM|
|River Wye New bylaws to protect salmon efective 1.9.2003||Aquazur-Dra||UK Game Fishing||0||October 10th, 2003 01:08 PM|