NNNSI "Broad Sweep" Invasive Alien Species Survey - How many have you seen?

Humans are increasingly moving species outside their natural range, sometimes deliberately and sometimes accidentally. In the absence of their natural enemies, some species can spread rapidly and cause problems. These species are termed ‘invasive’.

Invasive non-native species are considered to be one of the most important causes of biodiversity loss worldwide, second only to habitat destruction and fragmentation. They can also have significant economic impacts. One recent estimate put their cost at almost £2 billion a year in the UK alone!

The Broad Sweep project aims to reduce the impact of some of the worst invasive species in the Broads (LISTED BELOW). YOU can help by telling us when you see them. Without accurate and up-to-date information on the distribution of these species we cannot control them effectively.

THE BROADSWEEP PROJECT SPECIES ARE:

Himalayan balsam (Impatiens glandulifera)
Giant hogweed (Heracleum mantegazzianum)
Japanese knotweed (Fallopia japonica)
Floating pennywort (Hydrocotyle ranunculoides)
Red-eared terrapin (Trachemys scripta elegans)
American mink (Mustela vison)

IF YOU HAVE SEEN ANY OF THESE 6 NON-NATIVE SPECIES PLEASE USE OUR ONLINE RECORDING FORM (LINKS BELOW) TO TELL US ABOUT YOUR SIGHTING(S).

FOR MORE INFORMATION ON EACH OF THESE SPECIES SEE DETAILS BELOW THE ONLINE RECORDING FORM LINKS.

 



 

 

HAVE YOU SPOTTED ANY OF THESE 6 NON-NATIVE SPECIES?

The easiest way to send us information about the species you have seen is via our online form. Please select one of the three options below to send us your record:

 



(e.g. more than 20 records; including records of more than one species,
at more than one location and on several different dates 
- please send as excel spreadsheet where possible using our spreadsheet template below)

DOWNLOAD THE NBIS RECORDING SPREADSHEET HERE AND THEN CLICK ABOVE TO EMAIL US YOUR RECORDS
 (or email nbis@norfolk.gov.uk)


 



 

"BROAD SWEEP" INVASIVE SPECIES.....SOME BASIC INFORMATION:

 

Himalayan balsam
(Impatiens glandulifera)

Description: An annual herb up to 2m in height with pink/purple, slippershaped flowers, a fleshy stem and explosive seed heads.
Where to look: Prefers to grow in damp areas, and is particularly abundant on river banks where it out-competes native vegetation.
Why is it a problem? Die back in winter leaves river banks bare and susceptible to erosion.

ID Sheet  https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=33

 

Giant hogweed
(Heracleum mantegazzianum)

►Description: Large plant with umbrella-shaped flowers and sharply divided leaves, growing up to 5m tall. The stems are usually covered with sharp bristles, and have distinctive purple patches. Each flower can release up to 50,000 seeds!
►Where to look: Found in a variety of habitats, but common on riverbanks and roadside verges.
►Why is it a problem? The poisonous sap of this plant can blister skin.

ID Sheet   https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=30

 

Japanese knotweed
(Fallopia japonica)

Description: Tall herbaceous perennial with bamboo like stems covered with purple speckles. The shield shaped leaves are 10-15cm long with a flat base. White flowers in late summer.
Where to look: Widespread throughout the UK. Often found in or adjacent to, brown-field sites and along river banks.
Why is it a problem? The root system and strong growth of this plant can damage foundations. Dense colonies crowd out other herbaceous species. 

ID Sheet https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=369

 

Floating pennywort
(Hydrocotyle ranunculoides)

Description: This aquatic plant has characteristic, kidney-shaped leaves which can be free-floating or emergent. It has fleshy stems and fine, white roots.
Where to look: Emergent or floating on the surface of still or slowly moving freshwater.
Why is it a problem? With a peak growth rate of 20cm per day, floating pennywort can rapidly dominate a water body!

ID Sheet   https://secure.fera.defra.gov.uk/nonnativespecies/downloadDocument.cfm?id=31

 

Red-eared terrapin
(Trachemys scripta elegans)

Description: Grows up to 30cm in length and has a distinctive red stripe behind each eye. Other characteristic features are a pale belly and striped markings along the legs.
Where to look: Can often be found basking on the banks of water bodies.
Why is it a problem? These terrapins eat native bird eggs and insect larvae.

 

American mink
(Mustela vison)

Description: Mostly nocturnal, American mink has a body length of up to 50cm, with a tail about half as long again. It has a small patch of white fur on the chin, whilst the rest of the body is black/dark brown in colour.
Where to look: Close to rivers and lakes.
Why is it a problem? A voracious predator, American mink