Affinity Water, Colne Valley Fisheries Consultative and CABI combine to defeat Floating Pennywort
Affinity Water are supporting CVFC with their ambitious strategic plan to tackle Floating Pennywort in the Colne Catchment.
The Colne Valley Fisheries Consultative(CVFC) has been a long-time partner to the Centre for Agriculture and Bioscience International(CABI), sourcing, cutting and supplying Floating Pennywort(FP) to keep their stock of South American FP weevils alive while CABI conducted safety and efficacy trials to see if the weevil would eat anything other than FP and if they could be released into the environment to help bring this damaging invasive non-native plant under control.
CVFC and Affinity Water(AW) agreed that strategically the money would be best spent on the more sustainable and long-term development of the biological control offered by the weevil rather then the physical control of FP. A peer review and public/stakeholder consultation phase for the weevil release is now complete and a positive ministerial decision is imminent. A release licence for the weevil will follow and efforts to propagate and maintain healthy stocks of the weevil over the summer and autumn will be critical to build the culture up to numbers needed for releases.
CVFC recently presented a cheque for £30,000 to Djami Djeddour (senior researcher in the invasive species management team at CABI) to assist in maintaining the weevil stocks and making experimental field releases, with further money held in reserve should it be needed to assist with overwintering the weevil.
Tony Booker, chairman of CVFC and the driving force behind control work in the Colne river system, said, “Since colonising water bodies in the Colne Valley, floating pennywort has become one of the greatest problems some of our member clubs have had to face. Indeed, it has been a major factor in two of those clubs ceasing to exist as their main river fisheries simply became overwhelmed. CVFC demand led to the formation of the Colne Valley pennywort project and we have been involved since its inception.
We have led the way with continued involvement with CABI and it is our greatest pleasure to be able to continue that support – in this instance by making funding available for what we believe is the only viable long term solution”.
Djami Djeddour, senior researcher and manager on this project at CABI said “We’re very excited to finally have the opportunity to contribute to the strategic and coordinated management of floating pennywort across our waterways, after such a thorough period of safety testing. Weevils have a long history of success in the biological control of water weeds around the world. Support for the project from CVFC over the years has been invaluable and this generous contribution will help underpin the delivery of an agent that should help stop the spread and dominance of floating pennywort for the long term.
Melissa Ahmet, Senior Asset Scientist and Project Manager in the Environmental Enhancement Team at Affinity Water said “We are committed to protecting and enhancing the habitats of our native wildlife across our supply area. This work is essential to prevent the spread of Floating Pennywort, a non-native invasive species, which impacts waterbodies and threatens environmentally sensitive habitats. The Biodiversity Team at Affinity Water are happy to be working with CVFC and CABI to combine resources and expertise to improve the local environment.”
The Partners
Affinity Water is the public water supply company. Affinity Water provides 900 million litres of water each day to a population of more than 3.6 million people in parts of Bedfordshire, Berkshire, Buckinghamshire, Essex, Hertfordshire, Surrey, the London Boroughs of Harrow and Hillingdon and parts of the London Boroughs of Barnet, Brent, Ealing and Enfield. We also supply water to the Tendring peninsula in Essex and the Folkestone and Dover areas of Kent.
Affinity Water supplies the Colne Valley and have been an active partner with many conservation initiatives throughout the catchment, working alongside many partners.
Colne Valley Fisheries Consultative is a not for profit, volunteer led organization working for fisheries, anglers and the protection of the natural environment in the River Colne catchment.
CABI, the Centre for Agriculture and Bioscience International, is an international, inter-governmental, not-for-profit organization that improves people’s lives worldwide by providing information and applying scientific expertise to solve problems in agriculture and the environment and has been researching a weevil from South America which is a specialist Floating Pennywort natural enemy.
Floating pennywort is an invasive aquatic plant capable of covering water bodies in the UK, threatening delicate habitats, native plants, fish and insect communities. This plant has a rapid growth rate and can regenerate from small fragments. Management is mainly limited to mechanical clearance which is expensive, labour intensive and often ineffective. Through comprehensive specificity testing CABI aimed to identify the safest and most effective biocontrol agent to keep the plant in check in the invasive range.
The problem
Floating pennywort (FP), Hydrocotyle ranunculoides, is a strong contender for the title of UK World Beating Worst Aquatic Weed. Originating from Central and South America, the plant arrived in the UK in the late 1980’s as an oxygenating ornamental plant for the aquatic trade.
It didn’t take long however, for it to escape from private ponds and spread rapidly across England, the Netherlands and Belgium. It now impacts slow flowing river systems, canals and water bodies, forming dense vegetative mats, reducing the availability of oxygen in the water, threatening fish and invertebrates, choking drainage systems, crowding our native water plants and posing a risk to livestock, dogs and human health and blocking navigations.
Floating pennywort can grow up to 20cm per day and can regenerate from tiny fragments. With limitations on chemical use near water, management tends to largely rely on sustained and labour intensive mechanical and manual clearance which can exacerbate spread if the plant is fragmented.
This aggressive invader already costs £millions to control across Europe and Great Britain. Costs linked to its management and the negative impacts on tourism and recreational activities are estimated to exceed £25 million per year. Furthermore, impacts on biodiversity and habitats, through degradation of important wetland ecosystems and competition with native species are equally important, though harder to quantify.
Due to its significant negative impacts on biodiversity and the economy, it is listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales, making it an offence to plant or, otherwise, cause it to grow in the wild and it is banned from sale. As a species designated to be of European Union concern (EU implementing regulation (2016/1141), strict restrictions apply to the species and it cannot be imported, kept, bred, transported, sold, used or exchanged, allowed to reproduce, grown or cultivated, or released into the environment. This is a serious environmental problem plant.