Thriving beaver population 'threatens' Dutch flood banks By Anna Holligan

BBC News, The Netherlands Published duration 13 November 2012

image copyright Other image caption The Netherlands' beaver population is expected to grow from 700 to 7,000 by 2032

A thriving beaver population is threatening the stability of the Netherlands' sea defences, a group of experts has warned.

The Mammal Society has brought together other wildlife groups to work out how to protect these important water-blocking dykes from the small but potentially destructive semi-aquatic rodents.

Beavers play an important ecological role in the Netherlands and were initially brought in to increase biodiversity.

In forests, they gnaw through trees, creating space for other species to survive; in water they build dams, which allow insects and plants to thrive.

The beaver-breeding programme began in 1988, and since then the beaver population has grown exponentially. There are now an estimated 700 beavers residing in the country's streams and canals.

Triumphant mating habits combined with the beavers' ability to breed so successfully in the Dutch countryside mean they have been moving beyond the southern province of Limburg and entering towns and cities that may not be prepared for the influx.

With the Dutch beaver population expected to hit around 7,000 by 2032, the experts are conscious of the need to take pre-emptive action.

So far, there have been no beaver sightings in the capital, Amsterdam.

But beaver expert Vilmar Dijkstra assures me it is only a matter of time.

"When people have not had beavers before they do not know how to cope when they come and that is why we need to make sure we are all prepared."

'In their nature'

The Netherlands' famous dykes protect the land from being flooded: without these sea defences huge swathes of the country would be underwater.

In areas where the dykes are directly connected to the water, the beavers are starting to burrow through the ground.

There have been two cases that the Mammal Society is aware of, in which the water board has been called in to repair the damaged dykes.

Vilmar Dijkstra has been hosting the symposium and told us about some of the protective methods available.

"People can put down mesh grids underwater to stop the beavers from being able to get to the dyke, or use stones to protect them," he explained.

"It is only really a problem when the slope from the dyke is going steeply down into the water. That is when the beavers will like to burrow, because it is in their nature."

Mr Dijkstra says he is asking all the regional representatives one crucial question: "Are you beaver ready?"