Invasive Species

Invasive non-native species are defined as animals or plant species that have spread outside of their natural range and threaten native biodiversity. The Colne catchment has numerous invasive non-native species associated with the water environment such as Floating Pennywort and Signal Crayfish, which alter the biodiversity of the river system threatening native species.

The Landscape Partnership Scheme are leading an ’Invasive Species’ project to raise awareness of invasive species in the Colne Valley and provide advice to landowners and the public on effective control methods. The main focus of the project is on plant invasive species with a particular interest for Floating Pennywort, Hydrocotyle ranunculoides and Himalayan Balasm,Impatiens glandulifera, two abundant species which are detrimental to the local river systems.

Himalayan Balsam

Himalayan Balsam is a native species to the western Himalayans in North India. It was introduced to the UK in 1839 for ornamental purposes but escaped from gardens and became naturalised in Britain 1850s. It rapidly colonises the river banks and areas of damp ground at the rate of spread of 645km2 annually with seeds viable up to two years. The species is now well established across the United Kingdom and throughout Colne Valley Regional Park. The species grows in dense thickets along river banks, damp areas and wet woodlands. Each plant can produce up to 800 seeds which can be ejected up to 7m from the plant and spread along watercourses. The species dominates wet habitats suppressing the growth of native plant species and dies back in autumn leaving riverbanks bare throughout winter increasing riverbank erosion threatening our local rivers.

Invasive Species Identification and Control Guide for Himalayan Balsam

For more information about Himalayan Balsam download our Identification and Control Guides below.

Himalayan Balsam

Floating Pennywort

Floating Pennywort is a native species of North and South America. It was brought to Britain in 1980s as plant for tropical aquaria and garden ponds but escaped into the wild where it naturalised in 1990s. It spreads rapidly and is commonly found in south-east England and occasionally in north-west England and Wales. The species grows in shallow margins of slow flowing river systems and water bodies. The species is a major threat to Colne Valley rivers, the species can regrow from a single node and has a rapid growth rate, up to 20cm per day, forming dense matts of entwined vegetation, which dominate watercourses, obstruct boats, prevent angling, and outcompetes native species.

Invasive Species Identification and Control Guide for Floating Pennywort

For more information about Floating Pennywort download our Identification and Control Guides below.

Floating Pennywort

Giant Hogweed

Giant Hogweed is a species native to the Caucasus mountains in South West Russia and Georgia. It was introduced to the UK in 1820 for ornamental purposes but escaped from gardens and became naturalised in Britain in the 1828. It rapidly colonises the waste land and river banks creating detrimental affects on the riparian and aquatic environment as well as threatening human health due to its phytotoxic sap causing serve skin blistering.

Invasive Species Identification and Control Guide for Giant Hogweed

For more information about Giant Hogweed download our Identification and Control Guides below.

Giant Hogweed@NNSS

Japanese Knotweed

Japanese Knotweed is a native plant species in Japan, China and Taiwan. It was introduced to the UK in the mid 19th century for ornamental purposes but escaped from gardens and became naturalised as early as 1886. Japanese Knotweed is a tall herbaceous perennial with bamboo like stem, which grows in dense thickets commonly found in disturbed areas such as urban environments, riverbanks and transportations routes.

Japanese Knotweed has been spread across the United Kingdom through human transportation routes and watercourses moving fragments of the plant. The spread of the species has detrimental affects on the riparian and aquatic environment ‘as well as human economy’.

Invasive Species Identification and Control Guide for Japanese Knotweed

For more information about Japanese Knotweed download our Identification and Control Guides below.

Japanese Knotweed

Biosecurity and Prevention

Invasive species can spread accidentally through natural transport routes such as rivers, wind, animal migration as well as through human transportation such as boats and footwear, therefore it is important to follow good biosecurity controls to reduce the risk of introducing or spreading invasive non-native species (and other harmful organisms such as diseases) in the wild it.

They can be small and hard to spot so are easily spread on damp equipment and clothing. You can help to protect the environment and activities you enjoy by keeping your kit free of invasive plants and animals using simple method:

  1. Check your equipment, boat, and clothing after leaving the water for mud, aquatic animals or plant material. Remove anything you find and leave it at the site.
  2. Clean everything thoroughly as soon as you can, paying attention to areas that are damp or hard to access. Use hot water if possible.
  3. Dry everything for as long as you can before using elsewhere as some invasive plants and animals can survive for over two weeks in damp conditions.

To find out more check out the check clean and dry campaign here http://www.nonnativespecies.org//checkcleandry/index.cfm?

Help stop the spread of invasive species on our land and in our water!

Non-native Invasive Species Reporting

Non-native invasive species and wildlife disease can have significant impacts on biodiversity, human society and its economic interests. About 10-15% of non-native species established in GB cause significant adverse impacts. If you spot any non native invasive species in Colne Valley Regional Park please report your finding to CVFC NNIS database to help identify current population and direct future control action. This NNIS reporting system helps us track these species and involve the appropriate authorities.

To find out more or report NNIS, go to the CVFC NNIS page.