Medicinal Leech Recovery Project

Urgent action is necessary to stop Britain’s Medicinal Leeches from going extinct. Freshwater Habitats Trust is launching a new collaborative recovery project to enable a consortium of organisations to begin conservation action at the leech’s three main remaining locations, while engaging thousands of people in the conservation of this spectacular but misunderstood species.

Medicinal leech (c. Neil Phillips)

The elusive Medicinal Leech Hirudo medicinalis, the UK’s largest leech, is an iconic freshwater animal with striking vivid orange and yellow markings. They are found in ponds and ditches, where they commonly feed on frogs and provide an important part of the food web. The Medicinal Leech is also entangled in British medical history, as during medieval times they were common, and often used as a medicinal cure. Even today, leeches are essential for medicine and are still used to increase blood circulation.

Medicinal Leech Pond in Cumbria

However, the numbers of Medicinal Leeches in Britain have declined spectacularly. Once found in high abundance at hundreds of sites, there are now only three main populations present within Kent, Hampshire and Cumbria. In England this unusual species has been pushed to the edge of extinction. Their decline was initiated by the historical medical trade, when millions of leeches were exported abroad. More recently it has been changes in land use, wetland drainage and loss of grazing that have contributed to their rapid declines. Medicinal Leeches are now a global conservation priority, and are listed under a raft of international legislation, including: Appendix III of the Bern Convention; Appendix II of the Convention on International Trade in Endangered Species (CITES); Annex V of the Habitats Directive, and the IUCN red list.

The following activities have been identified by national experts as necessary to secure the recovery of England’s Medicinal Leeches.

    1. Collation of knowledge and data to document and understand the decline of England’s Medicinal Leeches.
    2. Establishment of eDNA monitoring – this new survey method will make surveying for Medicinal Leech easier, and will include widespread volunteer engagement through the surveys at 25 sites across England.
    3. Collaborations with zoos to secure three populations through living ‘Ark collections’, to provide a living gene bank in case of wild extinctions.
    4. Raise the profile of Medicinal Leeches through three zoo displays and six events that engage thousands of people with their conservation.
    5. A collaborative workshop to define and initiate national level conservation actions, engaging 30 partners, land managers and key volunteers.

By the end of the project, we hope to achieve the following outcomes:

    • Literature review and mapping of the Medicinal Leech’s distribution, available online through the Freshwater Habitats Trust website, to inform future activities.
    • Environmental DNA (eDNA) survey method established and in use, providing a more accurate assessments of Medicinal Leech distribution and pond occupation.
    • An ‘ark’ of individuals from the three main remaining populations in three zoos to act as a living biobank and provide a genetic safety net – also providing long-term support for reintroduction projects, to broaden their distribution and increase species resilience.
    • These zoo-based ark populations will provide huge outreach opportunities via displays, events and interpretative information, to engage thousands of visitors in the conservation and ecology of this unique leech.
    • A comprehensive Conservation Action Plan with sign up from partner, with its implementation started to deliver collaborative long-term conservation actions on all three main English populations.


Click on the link below to find out more…… 

This project is kindly sponsored by:

    • Swire Charitable Trust
    • Linley Wightman Shaw Foundation Trust
    • Chapman Charitable Trust
    • The Banister Charitable Trust
    • D’Oyly Carte Charitable Trust