Invasive non-native species are a serious and constant threat to British wildlife. The latest skirmishes in the continuing battle against them have taken place in the Stour Valley and on the Suffolk coast.

East Anglian Daily Times: Stour Valley Project officer Alex Moore da Luz with an invasive non-native Himalayan balsam plant at Tunmers Farm, Higham. Picture: GREGG BROWNStour Valley Project officer Alex Moore da Luz with an invasive non-native Himalayan balsam plant at Tunmers Farm, Higham. Picture: GREGG BROWN

It may be a war in which total victory will never be grasped - but conservationists keep fighting the battles anyway. And Suffolk has recently seen some spirited skirmishes in the onslaught against invasive, introduced non-native species - an array of aggressive aliens that kill, choke or out-compete local wildlife species that simply cannot cope against them.

The frontline has spanned the county in recent days.

The Stour Valley Invasive Non-Native Species Local Action Group held its annual meeting to discuss tactics and strategy in the continuing conflict - and on the very day the group gathered, on the other side of Suffolk an RSPB staff and volunteer group was grappling with one of the enemies on one of the charity’s coastal nature reserves. A few days later Stour Valley Project and Dedham Vale Area of Outstanding Natural Beauty volunteers also got to grips with an enemy in another hands-on assault on the aliens.

It’s a never-ending fight, and one in which it will never be possible to claim an everlasting victory as the non-natives problem is so diverse and widespread that such species can never be totally eradicated. However, conservationists continue to try to at least keep the most rampant and damaging aliens in some sort of check.

East Anglian Daily Times: A volunteer tackles Himalayan balsam at Tunmers Farm, Higham. Picture: GREGG BROWNA volunteer tackles Himalayan balsam at Tunmers Farm, Higham. Picture: GREGG BROWN

The Stour Valley action group meeting was held at the River Stour Trust’s education and visitor centre at Great Cornard and focussed on three alien species - giant hogweed, mink and Himalayan balsam.

Stour Valley Project officer Alex Moore da Luz told the meeting that, over time, giant hogweed had become a widespread problem in the Stour Valley area - and a huge amount of work with landowners, contractors and volunteer groups was taking place. Between February and this month, for example, he said that giant hogweed had been tackled at 26 sites and 4,023 plants had been removed.

Highly targeted spraying with Glyphosate was “part of the mix of measures” being employed but the “long-term plan” was to increase the use of manual control methods and hopefully to deploy more volunteers at more sites.

Mr Moore da Luz stressed it was important to appreciate that the only species of hogweed involved in the control effort was giant hogweed. It had detrimental ecological impacts but could also cause serious health problems for humans, with contact with its spiky hairs on stems and leaves sometimes causing burns and blisters - however, native hogweeds presented no problems.

East Anglian Daily Times: A volunteer adds to the huge pile of uprooted Himalayan balsam at Tunmers Farm, Higham. Picture: GREGG BROWNA volunteer adds to the huge pile of uprooted Himalayan balsam at Tunmers Farm, Higham. Picture: GREGG BROWN

Himalayan balsam was “so prevalent and so widespread” that it was commonly found on the River Stour and its tributaries the Brett and the Box.

Six work parties were due to tackle the invasive plant this year, at Bures, Shelley, Boxford, Nayland, Stratford St Mary and Higham, and Alphamstone - this week, one of the work parties got to grips with the species at Tunmers Farm, Higham. River Wardens helping with conservation in the Stour Valley area had worked tirelessly on Himalayan balsam and last year had removed about 1,500 plants, he said.

A note of cautious optimism over the control of mink in Suffolk was sounded by Nick Oliver, the officer for the Suffolk Mink Project which is part of Suffolk Wildlife Trust’s Water for Wildlife initiative. The non-native mink is the voracious nemesis of many native species, particularly in wetlands, and is especially linked to the decline of the UK’s water vole population.

Between 2002 and 2016 a total of 2,737 mink had been trapped in Suffolk, including on county border rivers, said Mr Oliver. Last year, the number caught was 65 - the lowest total since the project began. “Things are looking promising, and water voles are returning to many areas where they were only found in very low numbers previously, ” he said.

He had not seen any evidence of otters - a species that had recovered well in Suffolk - having any major impact on mink numbers and it was not yet known if the recently re-colonising polecat would affect their numbers either. Mr Oliver added.

While the action group meeting was taking place, an assault on invasive Himalayan balsam was taking place about 40 miles to the east. A work party tackled the plant at the RSPB’s North Warren nature reserve, near Aldeburgh - it was yet another skirmish in the continuing battle against a wide range of alien species that are causing major problems for British wildlife.

More information about invasive non-native species can be found at www.environment-agency.gov.uk