Upstream Struggle
'Seahorses in the Thames!' screamed a recent newspaper headline, marvelling in the discovery of the short-snouted version of the tiny creatures - once believed to pull Neptune's chariot - in the brackish river estuary in Essex.
But there is another marvel of our village's aquatic artery which is just as rare - and, sadly, likely to remain so. The salmon, once prolific in the Thames, is now maintaining a profile as low as a Labour candidate at a local election. While not quite extinct (the salmon, that is, rather than the Labour candidate) the majestic salmo salar is proving elusive in the extreme, in spite of sterling efforts by the Environment Agency and concerned conservation bodies to re-introduce it to the river.
It was not always so. The Thames was once so full of salmon that the fish was regarded as a poor man's food (along with oysters - how times change). But the onslaughts of the Industrial Revolution, including the building of weirs and locks to make the river deeper to enable boats to pass, plus the perils of industrial pollution and sewage, saw them off more than 170 years ago. One has to go back to 1833 to record the capture of the Thames' last native-bred fish.
Since then, no salmon had been seen in the river for 140 years when, on November 12 1974, a single stray salmon from another river was found alive - trapped on the cleaning screens at West Thurrock Power Station. After that, only the odd stray salmon was seen every year. It looked like the end of the line for the 'silver tourist'.
However, some things are worth saving: the salmon is one of them. In 1979, following umpteen committees and recommendations, the Thames Salmon Rehabilitation Scheme was launched. Its remit was ambitious: to demonstrate that London's river, known for 150 years as a running sewer, was clean again. So clean that salmon - nature's barometer of water purity - would once again be seen leaping outside the Houses of Parliament, surging their way up-river past Thames Ditton Island and Hampton Court on their way to their spawning grounds at the head of the river.
The project was launched with fanfare, high hopes, a great deal of goodwill - and not very much money. Initially, immature salmon from other rivers were transported to the tidal Thames, where it was hoped they would head to the open sea, as all young salmon do, then return to spawn and raise a new generation. First results were hopeful: thousands of young fish were stocked and initially, having spent their first few years feeding and fattening in the open briny, they returned in substantial numbers, proving that the lower Thames was cleaner than even the optimists had thought.
Tens of thousands of juvenile salmon have been released every year since in a major stocking programme. In tandem, the Thames Salmon Trust, a charity partly resourced and funded by anglers, organised (at a cost of £3m) the building of 39 fish passes built into the weirs and other obstacles between the lower Thames, where spawning potential was not good, and the middle reaches of the River Kennet in Berkshire, a noted chalk stream thought to offer best spawning potential due to its water quality. (The nearest fish pass to Thames Ditton is to be found just upstream at Molesey lock.)
In the early years all looked well. The numbers of returning fish increased. A prize was offered for the first angler to land an authenticated salmon on rod and line, and on August 23, 1983, one Russell Doig, a Londoner, caught a six-pounder. The triumphant publicity picture of Doig and his fish featured Tower Bridge in the background - a bit of PR cheek as the fish was actually caught at Chertsey. And in 1993, 338 fish were recorded - a record. Alas, the early '90s proved a high point. In 1996 anglers took just 34 fish in the season. And the bad news continued. In 2005, not a single fish was recorded as returning from the sea, the first time this had happened since the rehabilitation scheme launched in 1979. Just as disappointing, not one single salmon has been known for certain to spawn in the river. Every single returning fish so far has been one previously stocked.
The finger of suspicion has been pointed at many things. The near drought-summers of a few years ago decreased the water flow in both the headwaters and the Thames, meaning fish could not so readily swim upstream. Hot summers also warm the water and decrease the oxygen content available to all fish. Abstraction of water for housing and industry has increased significantly in the past couple of decades. And heavy rain and near flash flooding in the past couple of years has at times overwhelmed our aging sewerage infrastructure, leading to mass fish kills as raw sewage is pumped straight into our river. Natural predators such as pike and - increasingly - the normally sea-dwelling cormorant also take their share.
Now, 29 years and £6 million later, the project is not dead, but its future lies in the balance. The latest - and possibly last - attempt to save the salmon lies far upstream of Thames Ditton, in a stretch of the Kennet between Newbury and Hungerford. Here, on the bright gravel bed of this lovely river, the Environment Agency has experimented with direct 'sowing' of 20,000 fertilised salmon eggs, brought from the river Tyne in Northumberland. Some 5,000 juvenile salmon, about 2cm long, were also introduced. The hope is that the fish would head down river to the sea, through Thames the things you have to go through to breedDitton and central London, before returning after a couple of years to spawn anew.
Alas, first signs have again proved disappointing. "It's been incredibly disappointing," Darryl Clifton-Dey, who runs the project for the Environment Agency (EA), said. "There is still time for a turnaround. In 2003 we thought we were getting there. We tracked fish right back to the River Kennet, where we had put them in as juveniles. But we don't know if they actually did the business."
If they did spawn, Clifton-Dey said, their progeny should be in from the sea soon. "But if they didn't, and if we haven't had a successful spawning by April 2009, when the five-year programme ends, we'll have to look again. We'll have to determine whether there's a future for salmon in the Thames."
So, it's fingers crossed once again - especially for me. Because I really, really want to catch one...
Andy Anderson
Andy is a former member of the Financial Times editorial staff