ANGLERS are on the warpath and the surprising target of their anger is the swan. They, and owners of fisheries, report serious problems with the large numbers of swans on some of the finest chalk rivers in southern England.
The alleged crime of the elegant mute swan, or Cygnus olor, is that it devours tracts of an important river weed, Ranunculus or water crowfoot, that provides a protective cover for fish such as brown trout. This habitat is also a breeding ground for flies and other invertebrates that the fish rely on for food.
Some angling associations are suggesting that swan numbers need to be controlled.
The issue is sensitive. It is not just that the Crown technically owns all unmarked mute swans in open water, although the Queen as Seigneur of the Swans claims ownership of the birds in certain parts of the Thames and its tributaries. The swan is also a protected species and it is against the law to meddle with them. And there is the bird’s place in the national psyche. Ministers at the Department for Environment, Food and Rural Affairs (Defra) want no part in any measure that would be seen as a death warrant.
The issue has been raised with Ben Bradshaw, the Minister for Nature Conservation and Fisheries, by the Wiltshire Fisheries’ Association, the Salmon and Trout Association and the Anglers’ Conservation Association. He is about to approve more licences to shoot cormorants, which are ravaging fish stocks, but has said that he will not approve a cull for swans.
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Even conservation bodies recognise that the impact of the swans on the vital river weed is serious and experts at Defra, English Nature and the Environment Agency are working on the problem. But it is not just about an explosion in swan numbers.
There is no official count for swans nationwide, although David Barber, the Queen’s Swan Marker, counted 875 on the Thames in July, a rise of about 3 per cent. Elsewhere, English Nature says, numbers appear to be up because swans no longer suffer lead poisoning from the weights once used by anglers. Some former grassland next to rivers is also used to grow crops that provide the birds with an extra source of food.
The impact of the swans has more to do with diffuse pollution, over-abstraction, inefficient sewage treatment and run-off from pesticides on river weed. There is much less Ranunculus grown in rivers and the swans are eating what there is.
Conservation experts are convinced that in the long term the problem will be addressed by greener farming practices and cleaner waters that will restore the normal cycles of river systems.
In parts of the upper Avon, the Woodford Valley of the Avon, and its tributaries, the Wylye and Nadar, swans are seen as pests. Mike Trowbridge has been river-keeper at the Earl of Radnor’s Longford Estate along the Avon near Salisbury for 24 years. He said: “The problem on our stretch is that a pair of black swans have turned up to breed and have taken over a section of the river. The other white mute swans have now gathered in a group of 60 and have decimated a whole section of the river.
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“With the river stripped of weed the water level has dropped from 3ft to 18in. It is easier for cormorants to get at the fish and it is also affecting the fly life and the reproduction cycle of flies.”
He thinks that the numbers of swans must be reduced. “I think the best way would be to deal with the eggs and cover them in paraffin oil or prick a couple in each nest and just leave the others and the numbers will fall,” he said.
Paul Knight, the executive director of the Salmon and Trout Association, said: “We are not blaming swans directly. The problem is environmental degradation. If there was enough water producing enough weed then the swans would not have any impact.”
The Environment Agency confirmed that swans are now “a major issue” on chalk rivers, particularly in Hampshire and Wiltshire. It said that the main problems were flocks of immature juveniles occupying sections of river away from nesting adults who defend their territories. These flocks numbered from about 50 to 120 swans in certain stretches.
Officials are awaiting a scientific report on the ecological damage caused by swans before deciding how to deal with them. Defra confirmed that ministers were aware of the problem but were waiting for advice from experts.
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