INNS along the Aire

Every year, around now, our thoughts turn to how we are going to deal with the problem of invasive species in our rivers. We have been campaigning and acting for years on this topic, most especially in connection with the nasty Giant Hogweed. Other species pose a threat to wildlife, property of flood risk but GH poses a serious risk to human health. The sap, if it gets onto your skin, will cause long-lasting photosensitive burns. It needs totally eliminating.

Fortunately, thanks largely to funding by the Environment Agency, substantial progress has been made along the Aire and there are few occurrences above Esholt; the same cannot be said below there, so we were especially pleased to hear that the EA and Yorkshire Water are to fund ongoing work to control and hopefully eliminate not only GH but also other important species. The text below is from a briefing recently issued by the EA:


The Environment Agency have a Yorkshire INNS Strategy for Flood Defence Works. This targets three key species (Japanese Knotweed, Giant Hogweed and Floating Pennywort) for potential management.

As a result the Environment Agency will be undertaking the following INNS-related work in 2019/20:

  • Surveying for Japanese Knotweed, Giant Hogweed and Floating Pennywort on the following main rivers: Swale / Ure / Nidd / Ouse / Wharfe / Hull. There will also be additional discrete surveys for 5 more INNS on the headwaters of these rivers (Himalayan balsam, Orange balsam, giant butterbur, American skunk cabbage, monkey flower). All this data will be supplied to YWT by a bulk upload at the end of the survey year;
  • Treating Floating Pennywort on the main rivers of the Don, Calder and Aire. To this aim we will continue to work in partnership with the Canal and Rivers Trust to manage this species on all of Yorkshire’s rivers and navigations;
  • Treating Japanese Knotweed and Giant Hogweed on the following main rivers of south & west Yorkshire:
  • The River Aire (and associated main river tribs) from its headwaters in Malham down to the confluence with the Ouse;
  • The River Calder from headwaters to Luddendon Foot and also at Dewsbury;
  • The River Rother (and associated main river tribs) from headwaters to confluence with the river Don at Rotherham;
  • The River Don from (approximately) Rotherham down to the confluence with the Ouse;
  • The River Dearne (and associated main river tribs) from headwaters to confluence with the river Don.

Some additional points:

As before, all our INNS work will be undertaken by our framework contractor the River Stewardship Company;

  • Yorkshire Water are now a formal partner with us, and contribute financially to the above programme;
  • There will be targeted engagement with key landholders throughout Yorkshire (mainly Local Authorities);
  • There will be some additional targeted treatment of giant hogweed on the River Don upstream of Sheffield;
  • Will Kitts (Asset Performance Catchment Officer) and I sit on the steering group of the Yorkshire Invasive Species Forum (YISF), and we share all our INNS work through this forum;
  • Erica Adamson and I sit on the Yorkshire Floating Pennywort Forum and we share all our pennywort work through this forum.

For further information on invasive species work that the Environment Agency are undertaking please contact Andy Virtue at

Japanese Knotweed to be controlled by aphid?!

Japanese Knotweed control

Plans are afoot to try out a new approach to control of Japanese Knotweed.

Quite how The Independent came to pick up a year-old story I don’t know, but i am glad they did because I had not seen it before.

The article, in The Ecologist, describes how Japanese Knotweed has gone from being an ‘interesting new ornamental’ in 1847 to one of the biggest nuisances around. However, help is at hand in the name of a sap sucking herbivorous insect, Aphalara itadori . This little bug offers the prospect of natural bio-control, reducing the need for expensive and potentially ecologically dangerous herbicide remedies.

Releasing one non-native species to help control another may or may not be counter-intuitive! Watch this space.


Giant Hogweed again

Giant HogweedGiant Hogweed is not going to go away without some serious co-ordinated effort.

I make no apology for posting a BBC news item about Giant Hogweed from a couple of months back, when hogweed was heavily in the news. The incident reported here relates to a ‘trained horticulturalist’ who knows the problems yet still get caught out. What chance does an uninformed angler of member of the pybic have when they see this physically attractive weed?

We really must get even stronger co-ordinated action to remove this obnoxious weed form our catchments and The Aire Rivers Trust will be working with Yorkshire Wildlife Trust and others to raise the profile of the issue for several reasons:

  1. Pubic Health protection – it’s a serious risk to public health
  2. Linking up the various activities already underway
  3. Generating more funding to support the INNS project already being co-ordinated by the YWT
  4. Press the authorities to take stronger action – the Environment Agency have powers that they can exercise against anyone who fails to act against invasion

Don’t let the next victim be you, or your child!

If you see any, report it to the EA, to YWT, to us…or get yourself the handy Planttracker smartphone app and your report will be uploaded to the national database.

Giant Hogweed
Giant Hogweed blisters

Giant Hogweed near Carleton

Giant Hogweed identification
This is what it looks like

The Aire Rivers Trust is promoting action to identify and remove Giant Hogweed wherever it is found on our catchments.

Articles such as this one in The Craven Herald are valuable because they highlight the problem and draw the serious Health & Safety risks to a wider audience.

If you see anything that you think may be Giant Hogweed please DO NOT TOUCH. Keep well away from the plant and either record it using the free PlantTracker app or contact your local authority, the Environment Agency or Yorkshire Wildlife Trust  who are co-ordinating action in the area.

Giant Hogweed must be eliminated!

Giant Hogweed elimination on River Aire
Don’t touch Giant Hogweed!

We and others have written before about the dangers of Giant Hogweed – see here for example

Well, with increasing interest in ridding the countryside of this dangerous weed, the usual rash of press reports about the effects of getting the sap on skin, and with anecdotal observations suggesting that it is becoming widespread in our catchment, now might be the time for a concerted effort to eradicate it from our river catchment.

Just in case you have not realised the significance of this nuisance, the burns/blisters in the photo are what happens when the sap contacts the skin and the skin is subsequently exposed to sunlight. People have needed skin grafts after severe exposure. Don’t just take our word for it, visit the GB INNS Secretariat site or that of the Royal Horticultural Society – they know what they are talking abut!

The problem is that this is an ‘interesting’ plant, growing several metres high with attractive umbels of flowers – not unlike a giant “dead man’s oatmeal”  or Cow Parsley. Kids run around below the leaves and risk coming into contact with the sap, anglers brush past it or knock it down, and who knows what happens when animals come across it.

Giant Hogweed identification
This is what it looks like

The sap of the plant contains highly toxic chemicals known as furanocoumarins that can cause serious burns and blistering when it comes into contact with skin and is then exposed to sunlight. If the plant’s sap is rubbed into the eyes, it can cause temporary or permanent blindness. Its leaves, stems, roots, flowers and seeds all contain toxic components.

After contact with the plant, the burns can last for several months and the skin can remain sensitive to light for many years.

The NHS says anyone who touches giant hogweed should wash the affected area with soap and water, and keep it covered.

We are hoping to put together a collaboration designed to eliminate this pest. We will need money, technical support and volunteers. If you would like to help then please get in touch.

Finally, a copy of the INNS Secretariat’s Giant_Hogweed identification guide can be had by following the link.

Let’s get rid of Giant Hogweed

Giant Hogweed may be visuallGiant Hogweedy attractive, but it is a serious ‘health’ hazard because if you get the sap on your skin it forms seriously nasty weals/blisters and may leave your skin photosensitised for life. Getting the sap in your eye may blind you!

We want to get rid of this nasty plant – it often grows on riverbanks and the seeds are easily spread downstream, so control is really important and you might be able to help.

Yorkshire Wildlife Trust are offering some free training to volunteers who can commit time to controlling the weed. Here is the text of their email:

Do you know of anyone who would be willing to be trained to deal with invasive species on the River Aire in the Bradford Metropolitan area? We are having a big push to eradicate Giant Hogweed in this area. We can play our part in walking the banks and liaising with others to find the plants. Although we don’t have too much Giant Hogweed we do need to stop it expanding before its too late. There’s more about than was thought so dealing wHogweed bllistersith it is more urgent than thought previously.

There is a mammoth task for the EA and others in the Leeds area but the job in the Bradford area (Kildwick to Apperley Bridge) is a lot more manageable.

Please get in touch if you know of anyone who would be willing to undergo the free training offered by Yorkshire Wildlife Trust.