Invasive Species and Anglers: Check, Clean, Dry

By Alex Clayton · Updated 23 October 2026

Killer shrimp can stay alive for about 15 days in a damp fold of an angling net, according to research by the University of Leeds and Cefas. That is long enough to ride along to your next few sessions.

The invasive species UK anglers deal with are non-native plants and animals that damage fisheries once they get in. Anglers spread them on wet kit and by moving fish. The fix is Check, Clean, Dry every time you leave a water, plus a few hard legal lines: listed species must never be moved live, and in England no fish moves between waters without written Environment Agency (EA) agreement.

Below are the species to watch for, the law in England and Wales (with Scotland and Northern Ireland pointers), a kit-by-kit routine and how to report what you find.

Why Anglers Spread Invasive Species (and How Long They Survive on Kit)

You fish a club lake on Saturday and a river on Sunday, and the keepnet is still damp in the boot. That is exactly how invaders move between waters.

In research by the University of Leeds and Cefas, Dr Alison Dunn put killer shrimp survival in a damp net fold at about 15 days, and Dr Paul Stebbing of Cefas found signal crayfish persist for 3 to 7 days. Some invasive viruses and diseases last over a month.

A 2014 survey by Leeds and Cefas of more than 1,500 water users found that:

64% of anglers used their kit in more than one waterway within a fortnight
12% did not clean or dry it before moving
8% used kit abroad without cleaning or drying it on return

The Non-native Species Secretariat (NNSS) says over fifty invasive freshwater species have already been found in British waters. Once one is established, it is extremely difficult and expensive to get rid of, so prevention is the point. Moving fish or live bait is the second pathway, covered in the law section below.

The Invasive Species UK Anglers Are Most Likely to Meet

The invader most likely to ride home on your kit is a shrimp. The one that turns up on a bottom bait is a crayfish.

GOV.UK lists 30 invasive alien animals and 36 plants as species of special concern in England and Wales. Each is marked “widely spread” or “non-widely spread”, and that label changes what you should do. These are the invasive non-native species anglers meet most:

Species	What anglers notice	Status (England and Wales)	What to do
Signal crayfish	Large claws, takes baits on the bottom	Listed, widely spread	Never carry one away alive (see the law section)
Marbled, red swamp, spiny-cheek and virile crayfish; Chinese mitten crab	An unfamiliar crayfish or crab	Listed, non-widely spread	Report it
Killer shrimp (Dikerogammarus villosus)	A shrimp that is easy to miss in a damp net	Check the NNSS for its current status and distribution	Check, Clean, Dry every time
Topmouth gudgeon	A small fish; recorded at a few GB sites, under eradication	Listed, non-widely spread	Report it to the NNSS
Prussian carp, ginbuna, nigorobuna	Like brown goldfish or carp hybrids: deep-bodied, usually under 35cm, no barbels	EA fish movement controls on confirmed waters	Report it to the EA
Pink salmon	Large black oval spots on the tail, very dark mouth and tongue, small scales	EA wants every catch reported (odd-year runs expected)	Report it to the EA
Floating pennywort	Dense floating mats that can grow up to 25cm a day	Listed, widely spread	Remove it if you can; leave it on the bank
Parrot’s feather, curly waterweed, Nuttall’s waterweed; Himalayan balsam on banks	Weed beds and bankside growth	Listed, widely spread	Never move live fragments
Fanwort, broadleaf watermilfoil, alligator weed	Unfamiliar weed	Listed, non-widely spread	Report it on iRecord

Topmouth gudgeon competes with native fish, eats eggs and fry, and can carry disease. Floating pennywort regrows from tiny fragments, so a scrap in a landing net can start a new mat elsewhere, and its mats cut oxygen and can stop you fishing a stretch at all.

If you only learn two IDs, make them signal crayfish and floating pennywort. Both are listed as widely spread, so they are the two you are most likely to see.

What the Law Says: Listed Species, Crayfish and Moving Fish

A signal crayfish grabs your worm. Can you keep it, kill it, take it home or throw it back? The rules on invasive species differ across the UK, and in England and Wales the answer is precise.

Listed species

For listed animals you must not keep, sell, release, let breed or escape, import or transport them live, and that includes eggs. Listed plants carry the same rules for live parts and fragments. Natural England and Natural Resources Wales (NRW) handle licences.

Behind this sits section 14 of the Wildlife and Countryside Act 1981: releasing a non-native animal into the wild, or letting one escape, is an offence, as is planting a Schedule 9 plant there.

Crayfish on the hook

For a crayfish caught by accident, GOV.UK says:

Never take a listed crayfish away alive.
If you can humanely kill it, do so where you caught it.
If you can’t kill it humanely, release it immediately where you caught it, never anywhere else, and record it on iRecord.
If you’re unsure of the species, return it alive where you caught it. That protects native white-clawed crayfish.

The national rod fishing byelaws also ban crayfish, dead or alive, as bait or in bait in England. Trapping needs permission from the EA in England or NRW in Wales (see our crayfish trapping rules).

Moving fish and live bait

In England you need written agreement from the EA to transfer any fish or spawn from one water to another. Live bait is allowed only if it is kept at, and used in, the water it came from, and some local byelaws ban it outright. You also need the fishery owner’s permission to remove fish from club or private water.

In England, introducing fish, or possessing fish for introduction, without a permit can lead to prosecution and a fine of up to £50,000. The wider byelaws are in our guide to freshwater fishing rules in England.

In Wales, introductions fall under the Keeping and Introduction of Fish (Wales) Regulations 2014. Check the permit process with NRW.

If in doubt, leave it where you found it and report it.

Check, Clean, Dry: A Kit-by-Kit Routine for Anglers

The routine takes a few minutes at the bank, and the drying step costs nothing. These are the NNSS steps for anglers in bankside terms.

Check as you leave the water. Look over nets, waders, boots, keepnets, unhooking mats, bait boxes, buckets and any boat or float tube. Leave any mud, plant bits and small animals at the site.
Clean everything as soon as you can, paying attention to net mesh, wader seams and boot treads. Use hot water if you can (Fisheries Management Scotland also suggests disinfectant). The official guidance gives no set temperature.
Dry kit for as long as possible before using it elsewhere, because some species survive two weeks or more when damp.

Kit	Where invaders hide	Quick fix
Landing net and keepnet	Mesh folds, the slowest kit to dry	Shake out at the bank, rinse, hang fully open
Waders and boots	Seams, treads, felt soles	Brush treads at the bank, dry inside and out
Bait buckets and live-bait gear	Standing water	Empty at the water it came from
Unhooking mat and sling	Damp padding and folds	Rinse and dry opened out

After lure or feeder sessions, I’ve found the landing net is usually the last thing to dry, so it’s the first thing I hang up at home.

Two waters in one day. If you can’t dry kit in between, take a second landing net and keepnet, or fish the water you’re less sure about last. These are sensible habits rather than official rules.

Matches and club events. The NNSS says risk is higher where visitors arrive with kit, and publishes organiser guidance and an angling washdown poster. A washdown point on match days is part of good fishing etiquette.

Fishing abroad. Clean and dry everything thoroughly before it touches a home water, as the NNSS and Angling Trust both advise.

Good biosecurity fishing is dull. It works only if you do it every session, not just when a water looks suspect.

How to Report an Invasive Species (England, Wales, Scotland and NI)

A photo and an exact location are usually all recorders need. Take both, then report to the right body.

Nation	Who to tell	How
England	Environment Agency	24-hour hotline 0800 80 70 60; non-native fish to non-natives@environment-agency.gov.uk; pink salmon via the hotline or the EA reporting tool; plants and other species on iRecord
Wales	Natural Resources Wales	iRecord for records; the pink salmon tool was built with NRW; check NRW for its own reporting routes
Scotland	Fisheries Management Scotland	The FMS reporting tool for invasive species and disease, including signal crayfish and pink salmon
Northern Ireland	DAERA	Not checked for this guide, so contact DAERA directly

If you’re not sure what it is, report it anyway. Tell the club or fishery that controls the water too (see where you can fish), and use the fishing rules hub for the rest of the law.

Frequently asked questions

What does Check, Clean, Dry mean for anglers?

Check, Clean, Dry means checking kit for mud, plants and animals as you leave a water, cleaning it as soon as you can (hot water if possible), and drying it fully before using it elsewhere. Drying matters because some invasive species survive two weeks or more in damp kit. It is the core of biosecurity fishing.

Can I take signal crayfish home to eat?

Only once you have humanely killed them at the bank. You must never carry a signal crayfish away alive. Setting a trap needs permission from the EA in England or NRW in Wales, so read the crayfish trapping rules before you put one in the water.

Why do anglers need to worry about killer shrimp?

Killer shrimp is a harmful invader that spreads on damp kit. University of Leeds and Cefas research found it can survive about 15 days in a damp fold of an angling net. Check the NNSS for its current distribution and status before you fish new waters.

Can I move fish from one lake to another?

Not in England without written agreement from the Environment Agency. Live bait can only be used in the water it came from. In England, introducing fish without a permit can lead to prosecution and a fine of up to £50,000.