Most of us head out on the water for exactly the same reason. We want to enjoy nature, clear our minds, and leave the stresses of everyday life behind. But every time we launch a kayak, paddleboard, canoe, or fishing boat, we also have a responsibility to protect the very waterways we enjoy.
The sad reality is that invasive non-native species are becoming an increasing problem across the UK's rivers, canals, lakes and reservoirs. Many of these species don't arrive under their own steam. They hitch a lift on our kayaks, paddles, buoyancy aids, footwear, fishing gear, and even on the mud trapped in our trolley wheels.
The good news is that stopping their spread is actually very simple, and it only takes a few extra minutes after every paddle.
So, what are invasive species?
An invasive non-native species is a plant or animal that doesn't naturally belong in the UK. Once introduced, some species multiply rapidly because they have few natural predators here.
Unfortunately, they don't just live alongside our native wildlife; they often out-compete it.
Some of the biggest problems currently affecting UK inland waters include:
Zebra Mussels
These tiny shellfish attach themselves to virtually anything. Kayaks, trailers, ropes, pontoons and even water intake pipes can become completely covered.
They reproduce incredibly quickly, block waterways and damage equipment, while pushing out native freshwater mussels.
Killer Shrimp
Despite their dramatic name, they're only a couple of centimetres long, but they're extremely aggressive predators.
They feed on native insects and freshwater creatures, upsetting the natural balance of our rivers and lakes.
Floating Pennywort
At first glance it just looks like another aquatic plant.
The problem is it grows at an astonishing rate, forming dense mats across the water's surface. These reduce oxygen levels, block sunlight, restrict navigation and can make paddling almost impossible.
New Zealand Pygmyweed (Crassula)
This one is particularly difficult to control.
Even the tiniest fragment can start a brand-new colony. If a small piece sticks to your kayak or paddle and ends up in another waterway, you've unintentionally helped spread it.
American Signal Crayfish
Originally introduced for farming, they have become a serious threat to our native white-clawed crayfish.
Not only do they out-compete native crayfish, but they also carry crayfish plague, which is usually fatal to our own species.
Why should paddlers care?
It's easy to think, "It's only a bit of mud."
But that mud could contain microscopic eggs, larvae, plant fragments or tiny organisms that are impossible to see with the naked eye.
Move them from one river to another and you've potentially introduced an invasive species into a completely new environment.
Multiply that by thousands of paddlers every weekend, and you can see why the problem spreads so quickly.
Check – Clean – Dry
Thankfully, preventing the spread couldn't be much simpler.
✔ Check
Before leaving the launch site, take a few minutes to inspect everything.
Look over your kayak, paddle, trolley, buoyancy aid, dry bags, footwear and any other equipment.
Remove any mud, weed, leaves or anything clinging to your gear. Even the smallest piece of plant material could become tomorrow's invasive species.
✔ Clean
As soon as you get home, wash everything thoroughly using clean tap water.
Pay particular attention to places that are easily overlooked:
- Cockpit and footwells
- Carry handles
- Deck lines and bungee cords
- Scupper holes
- Rudders and skegs
- Kayak trolleys
- Footwear and boot soles
- Buoyancy aids and spray decks
Hot water is even better where practical, as it helps kill many invasive organisms.
✔ Dry
Once everything is clean, allow it to dry completely before using it somewhere else.
Many invasive species can survive for surprisingly long periods in damp conditions. Giving your equipment plenty of time to dry dramatically reduces the chance of transporting them to another waterway.
It's a small effort that makes a big difference
I've always believed that if we enjoy our countryside, we should also do our bit to look after it.
None of us wants to be the person who unknowingly introduces an invasive species into a beautiful river or lake.
Checking your gear takes a minute or two. Cleaning it might take another ten. Drying it costs nothing more than a bit of patience.
For such a small investment of time, you're helping protect the wildlife, habitats and waterways that we all enjoy.
The next time you finish a paddle, remember three simple words:
Check. Clean. Dry.
It really is one of the easiest ways every paddler can help protect our waters for future generations.
The organisations responsible for looking after our inland waterways spend a considerable amount of time and money trying to prevent the spread of invasive non-native species (INNS). Unfortunately, once many of these species become established, completely eradicating them is often impossible. Their focus is therefore on prevention, early detection, and containing outbreaks before they spread further.
Here's how organisations such as the Canal & River Trust (CRT), Environment Agency (EA), Natural England and local water authorities tackle the problem.
Public education
Probably the most effective weapon they have is education.
You'll often see "Check, Clean, Dry" signs at popular launch sites, slipways and visitor centres. Rangers and volunteers regularly speak to anglers, paddleboarders, kayakers and boat owners about preventing the spread of invasive species.
Campaigns are run throughout the year using websites, social media, leaflets and outdoor signage.
The simple aim is to change habits rather than rely on enforcement.
Monitoring and surveys
Authorities regularly inspect waterways looking for new outbreaks.
This includes:
- Water sampling
- Boat inspections
- Vegetation surveys
- Monitoring wildlife populations
- Reports from anglers and paddlers
Early detection is incredibly important. If a small outbreak is found quickly enough, there's a chance it can be contained before it spreads throughout an entire river or canal.
Mechanical removal
Some invasive plants can be physically removed.
Examples include:
- Floating Pennywort
- Water Fern (Azolla)
- Water Primrose
Specialist workboats fitted with cutting and harvesting equipment are used to remove tonnes of vegetation from waterways.
The downside is that this work has to be repeated regularly because many plants simply grow back.
Chemical treatment
Where appropriate, approved herbicides may be used on invasive aquatic plants.
This is carried out by trained contractors under strict environmental regulations to minimise harm to native plants and wildlife.
It's a carefully managed process and certainly not a case of spraying everything in sight.
Biosecurity procedures
Staff working on waterways follow strict biosecurity procedures themselves.
Boats, machinery, excavators, work platforms, nets and other equipment are cleaned before moving between different waterways.
Contractors are also expected to follow these procedures.
Containment measures
If a serious invasive species is discovered, authorities may introduce temporary restrictions.
These can include:
- Closing slipways
- Restricting boat movements
- Asking paddlers to avoid launching in affected areas
- Installing cleaning stations
The aim is to stop people accidentally transporting the species elsewhere.
Volunteer programmes
The Canal & River Trust relies heavily on volunteers.
Thousands of volunteer hours each year go into:
- Removing invasive plants
- Recording sightings
- Habitat restoration
- Public education events
Without volunteers, much less work would be possible.
Scientific research
The Environment Agency works alongside universities and environmental organisations to develop new control methods.
Research includes:
- Biological controls using natural predators
- Environmental DNA (eDNA) sampling to detect species before they're visible
- Improved monitoring techniques
- Better understanding of how invasive species spread
So where does the money come from?
A lot of people assume it's all funded by boat licence fees, but it's actually a mixture of different income sources.
Canal & River Trust
The CRT receives funding from several sources, including:
- A long-term grant from the UK Government (Defra)
- Boat licence fees
- Mooring fees
- Property rental income from its substantial property portfolio
- Donations from the public
- Charitable fundraising
- Legacies
- Commercial partnerships
- Grants for specific conservation projects
Interestingly, boat licences only cover a relatively small proportion of the Trust's overall income. The property portfolio and government grant are much larger contributors.
Environment Agency
The Environment Agency is a government body funded mainly through:
- Central Government (taxation)
- Environmental permits
- Waste regulation charges
- Fishing licence income
- Flood risk management funding
- Grants for environmental projects
The money used to tackle invasive species ultimately comes from taxpayers, licence holders and specific conservation funding.
Is it enough?
Speaking personally, I'd say most people working for the CRT and Environment Agency are doing the best they can with the resources available. The real challenge is the sheer scale of the network they manage.
The Canal & River Trust looks after around 2,000 miles of canals and rivers in England and Wales, while the Environment Agency manages thousands of miles of rivers, flood defences and navigation infrastructure. Monitoring every launch site, every paddler and every boat simply isn't possible.
That's why campaigns like Check, Clean, Dry are so important. If every paddler, angler and boater spends just five minutes cleaning their equipment after each trip, it saves authorities an enormous amount of time and money—and, more importantly, helps protect our waterways before invasive species get a foothold.
In many ways, protecting our rivers isn't just the responsibility of the authorities. It's a partnership between the organisations that manage them and the millions of us who enjoy them. Five minutes at the end of a paddle really can make a difference.



