Invasive Non-Native Species in the Wear Catchment
BIOSECURITY
Many freshwater and riparian invasive species are able to spread from one area to another hidden in our clothing, footwear or equipment. One way that we can reduce the likelihood of this happening is by following simple biosecurity measures, such as DEFRA’s Check, Clean, Dry protocol:
CHECK – Check clothing, footwear (including treads) and equipment for mud, plant material (e.g. seeds) or small aquatic animals before leaving the site and remove anything found while still there.
CLEAN – Clean everything thoroughly in hot water as soon as possible, making sure to include damp or hard to reach areas (if you are able to, do this while still at the site).
DRY – Leave everything to dry for as long as possible before using at a new site. Bear in mind certain species can survive for up to 2 weeks in damp conditions.
If you are planning to visit multiple sites, another useful tip is to make sure any sites where invasive species are not currently found (particularly any of significant ecological importance) are visited first while those where invasive species presence has been confirmed are left until last. Following this process will reduce the likelihood of invasive species being inadvertently introduced to new areas.
More information about biosecurity is available at http://www.nonnativespecies.org/checkcleandry/index.cfm
Japanese knotweed (Fallopia japonica) is a perennial weed that spreads rapidly. In winter the plant dies back to ground level but by early summer the bamboo-like stems emerge from rhizomes deep underground to shoot to over 2.1m (7ft), suppressing all other plant growth. Eradication requires determination as it is very hard to remove by hand or eradicate with chemicals. Knotweed can cause damage to built structures as it can grow through masonry and even concrete. It can remain dormant for several years and can vegetate from rhizomes. Fortunately it’s seeds are not viable in the UK.
Himalayan balsam (Impatiens glandulifera) is a relative of the busy Lizzie, but reaches well over head height, and is a major invasive weed, especially on riverbanks and waste land, but can also invade gardens. It grows rapidly and spreads quickly, smothering other vegetation as it goes. It spreads by seed dispersal, which are spread several metres by a catapulting action from the ripe seed pods. In winter it dies back, leaving river banks bare and more susceptible to erosion.
Giant hogweed (Heracleum mantegazzianum) is widespread in lowland GB, and is invasive along lowland rivers and on waste land. This umbellifer (member of the cow-parsley family) has flowering stems typically 2-3 m high bearing umbels of flowers up to 80 cm in diameter. The basal leaves are often 1 m or more in size. It is similar in appearance to the smaller native Hogweed (Heracleum sphondylium). Giant hogweed contains sap which, upon contact with bare skin can cause severe burns when exposed to the sunlight.
- REGIONAL STRATEGY
Wear Rivers Trust is now working with other organisations within the North East to create a region-wide INNS strategy to cohesively tackle invasive species across the Tweed, Northumberland Rivers, Tyne, Wear, and Tees catchments. This involves collaborating with the four other Rivers Trust associated with these areas, as well as Durham Wildlife Trust, the Environment Agency, Northumbrian Water and Environmental Records Information Centre (ERIC) North East, to compile invasive species records and share information. By learning from each other and pooling resources, it is hoped that a more efficient strategy for tackling INNS can be devised, increasing the likelihood that these species may one day be eradicated from the region.
Some other species to be on the lookout for in the Wear catchment and wider North East area include:
· Curly Waterweed
· Floating Pennywort
· Zebra Mussel
· American Skunk Cabbage
· Giant Japanese Knotweed
· Himalayan Knotweed
· Killer Shrimp*
These are currently less common in the region than Japanese Knotweed, Himalayan Balsam and Giant Hogweed, but must be monitored and sightings responded to quickly to prevent them becoming common and causing widespread damage.
*Killer shrimp is a GB alert species due to the devastating effect it could have on UK aquatic ecosystems. Any sightings of this species must be reported to the Centre for Ecology and Hydrology so the nation-wide response protocols which have been developed can be enforced quickly (more information is available here).
Other species to be aware of:
Pink Salmon, find out more here
Asian Hornet, find out more here
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