Invasive animals and plants in Britain

This video is called Fish Taxidermy – Zander.

According to British Waterways, the twelve most problematic invasive plant and animal species in Britain are:

1. Japanese Knotweed

One of the most invasive weeds in Britain, its dense growth crowds out native vegetation, erodes riverbanks and causes structural damage. Growing up to 3m high, this horror is common throughout Britain and can regenerate from tiny fragments.

2. Floating Pennywort

This fleshy-stemmed plant uses its roots to interweave a floating mat of lush foliage. But don’t be fooled by this former resident of tropical aquaria and garden ponds, this pestilential plant is a real problem – it grows very rapidly in late summer and is responsible for choking waterways, crowding out native plants and taking oxygen from fish and insects.

3. Giant Hogweed

This former ‘beauty queen’ of 19th century ornamental gardens, now found along waterways and areas of wasteland, grows up to 5m high. This dangerous, dark green giant produces thousands of seeds and can shade out other plants, increasing the risk of bank erosion. It also contains sap that can burn the skin when exposed to sunshine.

4. Australian Swamp Stonecrop

Sold in garden centres as an ‘oxygenating plant’, rapidly growing Stonecrop can quickly smother native vegetation. Spreading across the country since the 1970s, this yellow and green stemmed nasty can re-grow from tiny fragments and lives in a variety of habitats.

5. Water fern

The popular pond plant is also known as Fairy Fern but there’s nothing ethereal about this floating fiend, which forms dense mats of vegetation on the waters’ surface that may pose a hazard by appearing solid. Able to withstand British winters and invade a region very rapidly, this innocently sounding plant can reduce light beneath the surface, killing native plants and causing de-oxygenation.

6. American Signal Crayfish

Found throughout England, these brash 15cm-long beasts are aggressive, breed faster than the native species and damage banks with their burrowing. These filthy thugs also carry a fungal disease – ‘crayfish plague’, which is harmful to our native species.

7. Himalayan Balsam

Despite its soothing name, this densely growing pink and red-stemmed brute has an anti-social habit of projecting its seeds up to four metres away, allowing it to stifle native grasses and plants in its path. It dies back in Autumn but its destructive legacy lives on as it leaves waterway banks vulnerable to erosion.

8. American Mink

The bully of the inland waterway, mink are often mistaken for otters but are smaller and far more aggressive. An efficient predator, this menace – brought to Britain in 1929 for commercial fur farms – has a score to settle and will greedily dine on a variety of waterway natives, including fish, birds, invertebrates and Wind in the Willows’ favourite, the water vole.

9. Zebra Mussel

These stripey stowaways landed in Britain’s waterways on the hulls of ships from Eastern Europe and decided to stay. Growing up to 5cm long, the nautical nuisances reproduce rapidly and form large colonies that attach to almost any submerged hard surface, impeding the smooth running of canal gates and sluices.

10. Zander

This wide-mouthed predator has excellent vision and fang-like teeth, which it uses to eat native fish and steal their food. Highly adaptable, this voracious carnivore has now spread and thrives in large, slow flowing waters in Central England.

11. Chinese Mitten Crab

Named after their white tipped claws, these 8cm-long Asian crustaceans have a voracious appetite for almost anything that gets in their way. Their extensive burrowing damages canals, drainage embankments and structures – mostly in London, where they were found more than 70 years ago.

12. Red-eared Terrapin

Britain’s inland waterways were a safer place for bird eggs and insect larvae before these terrors came along. Brought to Britain from the USA as pets, these real life ‘Ninja turtles’, which can live for 25 years, are often dumped in the wild when they grow too big or their owner gets bored.

Invasive seaweed choking Scottish Lochs: here.

Results of British Waterways’ annual survey reveals diversity of waterway wildlife: here.

Invasive water plants in the Netherlands: here.

The green mussel is known for being a notoriously invasive fouling species, but researchers have just discovered that it also has a very powerful form of adhesion in its foot, as per a recent article in the Journal of Biological Chemistry. The stickiness of the mussel’s foot could possibly be copied to form new man-made adhesives: here.

ScienceDaily (Dec. 23, 2009) — Details of the lifestyle of mink, which escaped from fur farms and now live wild in the UK, have been revealed through analysis of their whiskers. Research led by the University of Exeter reveals more about the diet of this invasive species and provides a clue to its whereabouts. There are now plans to use the findings to eradicate it from environments where it can be devastating to native species: here.

September 2011: A project battling the damaging effects of mink on Scotland’s wildlife has just been extended for a further three years. The Hebridean Mink Project (HMP) will continue with an emphasis on monitoring until March 2014. This extension has been assisted by a contribution of £36,000 from Comhairle nan Eilean Siar (CNES): here.

4 thoughts on “Invasive animals and plants in Britain

  1. Abandoned pet terrapins causing havoc in the UK

    By Cahal Milmo

    11:47 AM Tuesday Jan 12, 2010

    Around Britain, the placid calm of urban ponds and watercourses is being disturbed by a rapacious new menace – legions of abandoned pet terrapins.

    It begins with the unexplained absence of frogspawn. Then comes the slow but steady disappearance of dragonfly larvae, fish and ducklings. In extreme cases, there are even vicious attacks on small dogs.

    Conservationists have issued a warning that hundreds of boating lakes, canals and waterways in towns and cities are infested with terrapins and small turtles which were bought as pets while brightly-coloured babies barely bigger than a 50p coin but dumped by owners unable to cope as they grew to mature carnivorous adults the size of a dinner plate.

    The trend began in the early 1990s when thousands of red-eared terrapins, each capable of living up to 30 years, were bought by young fans of the Teenage Mutant Ninja Turtle cartoon.

    But ecologists have warned of a more recent second wave of releases which is seeing additional species, including the aggressive snapping turtle, dumped in the wild.

    Although native to warmer climes such as America’s Mississippi valley, the terrapins and turtles readily take up residence in Britain’s parks and wetlands where they have a ready food supply, including young waterfowl.

    Experts have seen examples of ponds stripped of wildlife by a population of just two or three terrapins.

    Such is the scale of the problem that 51 terrapins and turtles, from five different species, were recently removed from a single pond in a north London park after the local authority called in a specialist trapper.

    Two years ago, a colony of 150 of the creatures was removed from the 25 ponds on Hampstead Heath and re-homed at a sanctuary in Tuscany.

    The result is a double headache for conservation groups as they try to control the problem by trapping and removing the unwanted invaders but struggle to find new homes for the captives because of their longevity (some species can live for up to 50 years) and the costs of running a dedicated aquarium.

    One sanctuary receives unwanted animal at a rate of six a week.

    John Baker, of the Amphibian and Reptile Conservation (ARC) Trust, said: “When these animals are bought as babies they seem attractive pets. But they grow to a significant size and people think it is OK to take them to their nearest body of water and release them into places where they prey on native species and can spread disease.

    “The additional problem is what to do with them once we find them. The law says they cannot be returned to the water and sanctuaries are often reluctant to take them. Caring for a terrapin is a major undertaking – they live for decades and we don’t want to see them put down. People really need to be more responsible about buying them in the first place.”

    As committed scavengers without natural predators in Britain, terrapins and turtles find themselves at the top of the food chain in urban ponds and watercourses, chomping their way through a menu of native species that includes newts, fish, toads, frogspawn, larvae and, for the largest and most aggressive specimens, the occasional duckling or juvenile moorhen and coot.

    Of particular concern is the common snapping turtle, a powerful American species, which has a vicious bite and is known for its aggression.

    One of the creatures was captured in the trawl of Clissold Park in Stoke Newington, which netted 51 critters, while another was suspected of carrying out attacks on several dogs and a Canada goose in east London.

    Rebecca Turpin, London officer for the ARC Trust, said: “We should not underestimate the impact that these animals can have. They can decimate a pond. I personally know of several where there is no wildlife left because of a few resident terrapins.

    “They can go through the native species pretty quickly if the conditions are correct.”

    The influx of red-eared terrapins to Britain in the early 1990s was halted by legislation banning imports of the species, but it has been replaced in the pet trade by a number of new types, including the yellow-belly slider, the Cumberland, the diamondback and the European pond turtle.

    Individual specimens can be bought for as little as £10 (NZ$21.70).

    Experts have consoled themselves with the fact that Britain’s climate means that although the terrapins and turtles can survive, they are unable to breed because cooling temperatures in the autumn do not leave fertilised eggs enough time to hatch.

    But the evidence in recent years is that a small numbers of juveniles has survived and prospered, raising the prospect of an established population across the British Isles.

    Wayne Rampling, a terrapin expert who runs a trapping service and sanctuary in Essex, carried out the week-long operation to clear the pond at Clissold Park. He said: “In many ways they are beautiful creatures.

    But they are in the wrong places and they are extremely adaptable. In London we found several babies which suggest very strongly that they are beginning to breed. When you add to that the fact that every female can have three sets of five-to-35 eggs, the implications are obvious.”



  2. t is thought global warming may be to blame as more tropical species make their home in the UK

    * There are about 44,000 ring-necked parakeets living in the UK, 90 per cent of which live in London, with other substantial pockets in East Kent. It is estimatd the population growing at a rate of 30 percent every year.
    * The birds originate from the Himalayas and there is a legend that a number who were brought to the UK for the filming of The African Queen in 1951 escaped.
    * In January this year, Natural England changed the law in relation to licences for dealing with parakeets. Ring-necked and Monk parakeets were added to the licence for preventing serious damage to crops. Monk parakeets were added to the licence for preserving public health or public safety.
    * Lasius neglectus, otherwise known as the Asian super ant, was spotted for the first time in the UK in Gloucestershire last year. The ants have also been seen in Germany, Hungary, France, Spain and Poland.
    * They look similar to the common black garden ant, but is very different in terms of its habits and breeding. It forms super-colonies which have a number of queens and interconnected nests which can spread across large areas.
    * Relatively new to the UK, these wasps tend to build their nests in hedges and shrubs. They are extremely fast to defend their nest site and will attack in large numbers if disturbed. They are very similar in colour to the common wasp but smaller.
    * Termites appeared in North Devon towards the end of the Nineties. It was thought that they came into the UK in a pot plant imported from the Canary Islands. The termites, which can rapidly destroy structural timbers, have reared their heads again after experts thought they had eradicated the problem.


  3. Pingback: Save white-clawed crayfish in Wales | Dear Kitty. Some blog

  4. Pingback: Invasive giant hogweed in Britain | Dear Kitty. Some blog

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