Skip to main content

The charity making life better by water

Tackling invasive species

Ecologist Tom King has outlined why tackling invasive species helps make life better by the water for everyone who visits.

  • Read the video transcript

    So, here we are on the River Weaver in Cheshire. And we’re here to talk about invasive non-native species and how we can all prevent them spreading through a process called ‘check, clean, dry’.

    So on the river, we have a real big problem with floating pennywort. And at the moment, the river’s clear. But in summer in late summer, it can completely cover the waterway.

    More than 50 non-native species have accidentally been introduced into our canals, rivers, and lakes from all over the world. And numbers are rising rapidly. They can cause major damage. They outcompete native wildlife, damage ecosystems, and spread disease. They can also block canals, causing a thick, green carpet, which restricts navigation, clogs up propellers, and damages boats.

    The Canal & River Trust is a charity, and every year, it costs us hundreds of thousands of pounds to clear unwanted vegetation and manage the delicate ecosystems which exist in many of our waterways.

    So, what harmful plants and animals do we need to watch out for? So, we’re talking about things like Japanese knotweed and giant hogweed, but also things that you might not see, freshwater shrimp or zebra and quagga mussels. Quagga mussels have even been found in an isolated angling reservoir in Lincolnshire. The nearest other known place with quagga mussels is London, which is over 140 miles away. So, how did this species travel overland for such a long distance? It probably hitchhiked on a person, on their equipment, tools, or machinery. Some species can survive for days, even up to a week, in a damp environment.

    So, how can people help? One of the most important things everyone can do is to stop the spread of harmful plants and animals to a new area. There are three simple steps to remember: check, clean, dry. This should be done before you leave a waterway, even if you’re only moving to another spot on the same waterway but a few miles away.

    The first step is to check any clothing, tools, or equipment have come into contact with the water – or even mud around the water. If you find any plant fragments or animals, remove them and leave them at the site. Ideally, bin them, but always make sure that they can’t get back into the water.

    The second step is to clean your clothing, tools, or equipment, ideally with hot water, but real good rinse with cold water will also dislodge bits of plants and young animals that you cannot see. Use a bottle of fresh water if you have one, or wash things down with a hose. Try and do it on a surface where the water can drain into the ground.

    The last step is to dry everything completely, ideally in the sun, leaving no damp patches.

    Don’t forget about clothes as well, things like wetsuits, waders on boots. Small invertebrates can live for days in damp folds and clothing, and seeds can get stuck in the tread of muddy boots.

    We’re here to talk about invasive species. Where would you check on your boat for invasive species?

    The most obvious places would be the weed hatch, the front and back fenders, mooring lines front and back and centre, anything that’s going to be touching the water, so boat poles, any cans or dippers that you might be using, anything that’s really making contact with the water. If you get anything around the propeller, then obviously you go into the weed hatch, and you have to get your arm in there and clear it. The most important thing then would obviously be to try and remove that, whatever you get. If it’s something like pennywort or something like that, to try and remove it from the canal.

    So, how regularly would you check and clean your boat?

    Okay, so if you’re going on a long journey, I would say that you need to do it at the start of the journey, and as frequently as possible really, preferably once a day. If you’re going from one waterway to another, then I would say so definitely do it. If you’re going from a river to a canal, then you might be transferring things from a river that don’t belong on a canal and vice versa, really. Things will dry off quite naturally in the open air, and there’s plenty of it out here really. But anything that you can dry off, you could do it like a car really with like a chamois leather or things like that, or you could think about having like a fresh set of ropes in a locker so every couple of days you could swap and change your ropes over after you’ve cleaned and dried them.

    So, where would weed or invasive species get caught on your boat, and how do you go about checking and cleaning it?

    We’ll get it caught in various places, like the riggers, the fin, the bowel ball at the bottom. If you capsize, you may get it in here as well. Going about cleaning it, would get a hot water and some sponge, give it a once over and try and get rid of every last bit of dirt.

    Where does weed or invasive species tend to get caught on a paddleboard?

    Well, Tom, they get caught in the very front on the valve seating, and as we come down to the board, you can see it gets caught in the luggage bungee cords here, and then, of course, as you come down to the footplate, you can see it gets embedded into the non-slip surface of the spot plate. And again, on the leash, you can see on the velcro on the leash, it really does capture it, you know, so it needs to be cleaned thoroughly and as we go further down onto the leash onto the D-ring it gets caught there. And, of course, if you turn the board over, you can see the fin at the back, it tends to get captured into the fin as well and the securing nook. And then finally, on your paddle. You get spores on the paddle as well, so of course, when you take it home, you must ensure you wash it clean with fully cold water. And any weed that you collect from your board is disposed of in a nearby bin or left on the land but not put back in the water.

    So, where is most important to check for invasive species in all your equipment?

    Okay, well, if you’re a canal angler, you’re on the towpath, actually, your box and equipment on the towpath isn’t actually as high risk. It’s the stuff that’s in the water where you need to check first, so you’ve got your landing nets, which you check looking for if anything that hits the ride and also if you’re a match angler and some pleasure anglers use these too, these are called keep nets, and this is where you put your catch in, and at the end of the session, you can see what you’ve caught. So, taking a keep net out, we will do, just as before, we’ll do a quick check to make sure there’s nothing in there. We shall tip it out. And look at there, straight away, we’ve got some plants that have sneaked in.

    So, we’ve all got a role to play to prevent invasive non-native species from spreading around. Remember the three simple steps of check, clean, dry – especially when you’re going to different waterways. Please help us to help the waterways we all love to stay special.

Why are invasive species such a problem?

More than 50 non-native species have been accidentally introduced into our canals, rivers and lakes from all over the world, and numbers are rising rapidly. This is potentially going to get worse with climate change.

They can cause major damage. They out-compete native wildlife, damage eco-systems and spread disease. They can also block canals, forming a thick green carpet which restricts navigation, clogs up propellers and damages boats. Every year it costs us hundreds of thousands of pounds to clear away unwanted vegetation and manage the delicate eco systems which exist in many of our waterways.

What harmful plants and animals do we need to watch out for?

People tend to know about things like signal crayfish from North America, Japanese knotweed or giant hogweed. But there are dozens of other problem species. These include non-native fish that gobble up all the other fish around them, and small invertebrates, like freshwater shrimp, that you may not even realise are there. Then there are lots of plants that may look nice, but can cause enormous damage to local biodiversity.

Plants, like floating pennywort or curly waterweed can grow quickly and thickly, up to 20cm a day. This rapid spread means that they then block the water, which in turn makes it hard for powered boats, sailing boats or even paddle sports to get around. Its rapid growth prevents people from using the water and there is a huge cost to keeping a passageway through clear of weed.

Other, not so obvious issues, include non-native freshwater mussels. As these are underwater, you may not see them. Species like zebra (picture below) and quagga mussels can grow inside pipes and water-cooled engines, which then result in big costs for the asset companies that need to clear them out.

Zebra mussels in line on rock

Quagga mussels have even been found in an isolated Anglian Water reservoir in Lincolnshire. The nearest other known place with quagga mussels is in London, over 140 miles away. So how did this species travel overland such a long distance? It most likely hitch-hiked on a person, on their equipment, tools or machinery. Some species can survive for days, even up to a week, in damp equipment.

For anyone living near a river colonised by Himalayan balsam, you'll know it can take over and crowd out other plants. This is bad for insects, mammals and birds. Himalayan balsam dies back every autumn, which then leaves the riverbanks bare and can lead to erosion and flooding.

How can everyone help?

Watch to find out how waterway workers, contractors, marinas, boat yards and hire boat companies can help with invasive species.

  • Read the video transcript (Invasive species control: contractors)

    Here we are on the River Weaver, working with our framework contractor Land & Water Services, to dredge the canal for navigation, and we’ve come here today to talk about how when we carry out works on the waterway, we need to implement biosecurity measures to make sure that we’re not spreading invasive species.

    More than 50 non-native species have accidentally been introduced into our canals, rivers, and lakes from all over the world. And numbers are rising rapidly. They can cause major damage. They outcompete native wildlife, damage ecosystems, and spread disease. They can also block canals, causing a thick, green carpet, which restricts navigation, clogs up propellers, and damages boats.

    The Canal & River Trust is a charity, and every year, it costs us hundreds of thousands of pounds to clear unwanted vegetation and manage the delicate ecosystems which exist in many of our waterways.

    So, what harmful plants and animals do we need to watch out for? So, we’re talking about things like Japanese knotweed and giant hogweed, but also things that you might not see, freshwater shrimp or zebra and quagga mussels. Quagga mussels have even been found in an isolated angling reservoir in Lincolnshire. The nearest other known place with quagga mussels is London, which is over 140 miles away. So, how did this species travel overland for such a long distance? It probably hitchhiked on a person, on their equipment, tools, or machinery. Some species can survive for days, even up to a week, in a damp environment.

    So, how can people help? One of the most important things everyone can do is to stop the spread of harmful plants and animals to a new area. There are three simple steps to remember: check, clean, dry. This should be done before you leave a waterway, even if you’re only moving to another spot on the same waterway but a few miles away.

    The first step is to check any clothing, tools, or equipment have come into contact with the water – or even mud around the water. If you find any plant fragments or animals, remove them and leave them at the site. Ideally, bin them, but always make sure that they can’t get back into the water.

    The second step is to clean your clothing, tools, or equipment, ideally with hot water, but real good rinse with cold water will also dislodge bits of plants and young animals that you cannot see. Use a bottle of fresh water if you have one, or wash things down with a hose. Try and do it on a surface where the water can drain into the ground.

    The last step is to dry everything completely, ideally in the sun, leaving no damp patches.

    Don’t forget about clothes as well, things like wetsuits, waders on boots. Small invertebrates can live for days in damp folds and clothing, and seeds can get stuck in the tread of muddy boots.

    So, Peter, we’re here with Land & Water Services to talk about invasive species, but what do they need to think about for check, clean, dry?

    Well, so the first thing to start with is all this big plant isn’t it? So, we’ve got diggers, we’ve got dumpers, we’ve got all kinds of vehicles here, and it’s all kit that will go from site to site. So, really, they need to make sure that when they bring it to a new site like this that it’s clean before it gets here. Check to see whether there’s any obvious mud or plant material or other stuff on the vehicle, particularly in the tracks or the bucket or anything that might have been in the mud or the water. If there is stuff, clean it off. A jet wash is fantastic on these kinds of big bits of kit. And then, if you’re moving stuff away to another site, make sure it’s dry before it goes somewhere else and then you can be sure that you’ve got rid of everything.

    So, what about smaller stuff like tools and equipment?

    Yeah, right, so obviously, on a lot of our jobs, people are using small kit like shovels and so on, and that’s just as important because as you can see from the state of this spade, yeah, there’s mud there that I might be transferring from one job to another. Now, if you’re on the same job for a long period of time, obviously you don’t need to worry about that. The kit’s not going anywhere. But if you’re on a more reactive team and you’re moving from one site to another in the same day, then clearly, we don’t want to be tracking this mud from the River Weaver up onto the Trent & Mersey or the Shropshire Union or somewhere else. So, it’s really important that again you check it and clean it, and if you can, dry it before you leave site.

    Another area that potentially we need to think about is your clothing, like your boots and anything like waders or anything. What about check, clean, dry with those sorts of things?

    Yeah, absolutely, Tom. So, a lot of our work is really mucky, so yeah, we are going to get covered in mud from doing works on the waterways, and so it’s very easy for us to transfer plants and materials from one site to another if we don’t clean ourselves as we go.

    Now, I’m not terribly muddy today, but I have got some mud on me boots there. And we don’t want to be tracing that off to another site. So, just check it to see if there’s anything on it that needs removing. Clean off what you can with water and with a brush, and then make sure that you dry it out if you can.

    So, what’s the risk about moving soil around and preventing invasive species being spread like that?

    Well, obviously, if you know you’ve got Japanese knotweed or Himalayan balsam or something like that on the site, then when you start excavating in this area, we don’t want to be picking any of that material up and moving it off-site because that would be spreading those invasive plants.

    We ask everyone to play their part. Please help us help keep our waterways, which we all love, special.

  • Read the video transcript (Invasive species control: boat hire)

    So, here we are today at Aqueduct Marina in Cheshire and we’re here to talk about how we can clean a boat that’s been taken out of the water, and that’s really important for maintenance, but also the really key thing is when a boat is being taken a long distance over land. And we’re here to look at how a boat should be cleaned to prevent the spread of invasive non-native species.

    More than 50 non-native species have accidentally been introduced into our canals, rivers, and lakes from all over the world. And numbers are rising rapidly. They can cause major damage. They outcompete native wildlife, damage ecosystems, and spread disease. They can also block canals, causing a thick, green carpet, which restricts navigation, clogs up propellers, and damages boats.

    The Canal & River Trust is a charity, and every year, it costs us hundreds of thousands of pounds to clear unwanted vegetation and manage the delicate ecosystems which exist in many of our waterways.

    So, what harmful plants and animals do we need to watch out for? So, we’re talking about things like Japanese knotweed and giant hogweed, but also things that you might not see, freshwater shrimp or zebra and quagga mussels. Quagga mussels have even been found in an isolated angling reservoir in Lincolnshire. The nearest other known place with quagga mussels is London, which is over 140 miles away. So, how did this species travel overland for such a long distance? It probably hitchhiked on a person, on their equipment, tools, or machinery. Some species can survive for days, even up to a week, in a damp environment.

    So, how can people help? One of the most important things everyone can do is to stop the spread of harmful plants and animals to a new area. There are three simple steps to remember: check, clean, dry. This should be done before you leave a waterway, even if you’re only moving to another spot on the same waterway but a few miles away.

    The first step is to check any clothing, tools, or equipment have come into contact with the water – or even mud around the water. If you find any plant fragments or animals, remove them and leave them at the site. Ideally, bin them, but always make sure that they can’t get back into the water.

    The second step is to clean your clothing, tools, or equipment, ideally with hot water, but real good rinse with cold water will also dislodge bits of plants and young animals that you cannot see. Use a bottle of fresh water if you have one, or wash things down with a hose. Try and do it on a surface where the water can drain into the ground.

    The last step is to dry everything completely, ideally in the sun, leaving no damp patches.

    Don’t forget about clothes as well, things like wetsuits, waders on boots. Small invertebrates can live for days in damp folds and clothing, and seeds can get stuck in the tread of muddy boots.

    So, when we’ve got our boats out, this is a really good set-up. It’s far enough away from the water, so anything washed off doesn’t end up back in the water course. It’s also a built environment, so all the invasive species that washed off get captured. There are then drains, so the wastewater gets captured as well, and doesn’t end up in another water course. All of this means that we’re not spreading invasive species to other watercourses. This set-up is also really good because the boat is slightly higher, which means that we can jet wash underneath, and that’s really key because invasive species will still cling there.

    So, the boat’s out of the water and you can quite clearly see how much material, plant material and even zebra mussels, are attached to the boat and that’s why it’s really important when a boat is coming out of the water and it’s being transported to somewhere else across land, or even just for maintenance, that the boat is really thoroughly cleaned. That check, clean, dry is really important when a boat is out of the water.

    We ask everyone to play their part. Please help us to help the waterways we all love to stay special.

How you can join the fight against invasive non-native species

One of the most important things everyone can do is stop the spread of harmful plants and animals to a new area.

There are three simple steps to remember: Check, Clean, Dry. They should be done before you leave a waterway, even if you are moving to another spot on the same waterway just a few miles away.

The first step is to Check any clothing, tools or equipment that have come into contact with the water, or even mud around water. Even the tread on your bike or the fur of your dog might be carrying an invasive species. If you find any plant fragments or animals, remove them and leave them at the site. Ideally, bin them, but always make sure they can't get back into the water.

Second step is to Clean your clothing, tools or equipment. Ideally with hot water, but a good rinse with clean cold water will also dislodge bits of plants and young animals that you can't see. Use a bottle of fresh water if you have one handy, or wash things down with a hose. Try and do it on a surface where the water can drain into the ground.

The last step is to Dry everything completely. Ideally in the sun, leaving no damp patches. Don't forget about clothes as well, things like wet suits, waders and boots. Small invertebrates can live for days in damp folds in clothing and seeds can get stuck in the tread of muddy boots.

Last Edited: 02 January 2024

photo of a location on the canals
newsletter logo

Stay connected

Sign up to our monthly newsletter and be the first to hear about campaigns, upcoming events and fundraising inspiration