Ebsford have been working closely with the Canals & Rivers Trust on the Canal & River Invasive Species Eradication Project 2021 – 2025. This project aims to eradicate invasive non-native species (INNS) that are present on CRT’s waterways and listed within the various legislation e.g. Wildlife & Countryside Act (1981, as amended) and the Invasive Alien Species (Enforcement & Permitting Order 2019). The four priority species include Japanese knotweed, Giant hogweed, Floating pennywort, and Water fern. The main drivers for the project are:
• Out-competing native wildlife and impacting other species critical to native biodiversity
• Damaging eco-systems and their functionality
• Posing a public and ecological health risk by spreading diseases and producing dangerous substances
• Blocking canals by forming thick green carpets on the water, impedes navigation, clogs up propellers and damages boats
• Increasing the potential risk of flooding
• Impacting water quality for native fish and aquatic plants
• Damaging infrastructure including canal banks and earth structures
In the Spring of 2022, a series of INNS surveys were undertaken along six Green Flag canals: Tame Valley & Walsall Lock; Wolverhampton Canal; Coventry Canal; Walsall Lock & Canal; Birmingham Main Line; and Worcester & Birmingham Canal. The main objectives have been to:
• Undertake INNS surveys (including non-priority species) along 112 km of the canal network in Birmingham and Coventry
• Record and manage the data within a Geographical Information System (GIS)
• Provide initial baseline data on a canal specific basis
• Undertake suitable management of main species
• Update the GIS records as the management progresses
• Provide update reports to CRT with geotagged photographs and supply updated GIS database
• React, confirm, and manage any new INNS reported
In total sixteen species were recorded along the canal network and included 13,250m² of Japanese knotweed, 680m² of Giant hogweed, and 2,148m² of Himalayan balsam. Data was collected using a GPS unit (GNSS, accurate to <0.5m) and QField, a customizable field recording mobile application capable of capturing not just the position and identification of a species but also other information e.g. location in chainage along the canal. The field data was then processed in QGIS, generating an updated INNS database in the form of areas (polygons), points or linear features, and maps. It was then used to prioritise infestations by identifying those on CRT land versus those on neighbouring land and those that were near watercourses that could spread downstream or habitats at immediate risk of degradation. This data was integrated into mobile applications (e.g. what3words and fulcrum) that enabled operatives to locate and record management activities.
In the Summer of 2022, the first management round was undertaken followed by a second in Autumn 2022 and then repeated again in 2023. Invasive Non-Native Species were managed in accordance with current best practice as defined by the two industry bodies: Property Care Association (PCA) and Invasive Non-Native Specialists Association (INNSA). The application of herbicides was reviewed by our BASIS qualified representative, and all applications were undertaken by qualified staff. Where INNS management occurred near a watercourse then records were kept in accordance with CRT’s MoU with the Environment Agency. Application methods were tailored to the species and also to limit non-target effects, by using for example stem injection, eco-plugs and weed wiping. Other legal requirements considered included nesting bird surveys as Japanese knotweed, Japanese rose and Cotoneasters can sometimes form structures suitable for breeding birds.
The successful management of INNS requires an understanding of the individual species life cycle and how these are influenced by the variations in the season. For example, Himalayan balsam spreads by seed after flowering in mid-summer, and Japanese knotweed spreads via specialised roots (rhizome) which store reserves for the following year in mid-late summer. As such management should target the Himalayan balsam before flowering (summer), and the Japanese knotweed during the mid/late summer.
