the GiGLer

The newsletter of Greenspace Information of Greater London CIC

Joy of Recording

Amelia Stodel

Ecology has inspired all aspects of my adventure-filled life

In the late 1980s, I briefly worked for the Essex Wildlife Trust as a Phase 1 Habitat Surveyor recording the plants and topography throughout the county. A couple of decades down the line, you would find me working in the Western Cape, South Africa, gathering records of indigenous flora in the fynbos biosphere. Plants have always been my main passion and the knowledge and training I gained from my experience as an ecologist helped nurture the awe and curiosity I have of the natural world.

I returned to the UK in 2011, moving into a house boat on a wharf at the junction of the rivers Brent and Thames. One day, while working on a small patch of garden on the wharf’s bank, I noticed a tiny little snail that I hadn’t previously encountered; after making enquiries around the neighbourhood, my landlord told me it was a Thames two-lipped snail (Balea biplicata).

A close-up of the Thames two-lipped snails © Minhyuk Seo

Contrary to the most recent ecological survey of the wharf, which reported all specimens of the Thames two-lipped snails as dead, my snails were very much alive and I had observed and recorded them in other locations along the canal and the banks of the Thames.

I started to research more in-depth and discovered that most live records of the snails were outdated; a small population was reported in Purfleet, Essex, 20 years ago and the Essex Wildlife Trust confirmed that no snails have been observed there since. Towards the end of 2018, I went along to a meeting with ecologists and volunteers for London Wildlife Trust’s Isleworth Ait and learned that there has been no live recordings of Thames two-lipped snails for the past three years.

Observing the snails through a bowled habitat © Minhyuk Seo

Having realised the population is probably restricted to a tiny corridor along the River Thames, I started to collect live specimens from the site and keep them in bowls on my foredeck (moving them into my wet room when conditions got too rainy). I observe the snails most evenings (they are dusk to dawn feeders), keeping them in leaf litter and supplying them food in the form of foraged twigs with growth of Xanthoria and Physcia lichen and cuttlebone as calcium supplements. Although quite time-consuming, the more I discover and learn about the snails, the more fascinating they become.

With my recording efforts accumulating, I came across GiGL in 2014, as recommended by my neighbour who worked at Kew Gardens, and submitted my records through the online form along with images of the live specimens. My records apparently make up a fifth of all Thames two-lipped snail records on GiGL’s species database which highlights the need for increased recording effort around my area; the more records that are sent to GiGL, the better we can understand London’s wildlife.

Having a comprehensive records base of the Thames two-lipped snail has never been more relevant as they are now under threat from planning works. The 17th century walls of the wharf are in desperate need of restoration and development has already begun, starting with the removal of mature trees that support the Thames two-lipped snails throughout their life-cycle. As a result, a lot of the specimens I am now finding are dead and only a few live individuals remain. Although globally a species of least conservation concern, they are rare, possibly native, species in Britain that are designated as a London BAP priority species.

Using up-to-date environmental records in making planning decisions is not about preventing development, as the walls of the wharf I live on are becoming unsafe, but alternative actions could have been made in advance to minimise the effects development has had on the Thames two-lipped snails.

The future however, looks more positive with regards to the snails’ potential extinction. I read a paper about a successful breeding and re-release program with the Partula tree snail in Hawaii and believe that a similar, controlled reintroduction programme may work for the Thames two-lipped snail too; I am currently in contact with various conchologists about its feasibility. If a suitable habitat can be found for such a programme, I have high hopes to be able to record these wonderful snails along the Thames for years to come.

6 Comments

  1. Dave Dawson on April 2019 at 4:50 pm

    In the 1990s, the main population of Balea (Alinda) biplicata, the Two-lipped door snail was a well-known area that became part of the grounds of a new housing development, Strand Drive, lying between the National Archives building and the Thames path and east of the railway track between Kew Bridge and Gunnersbury stations. There was a very large population, centred at grid ref: TQ19557739 and, in theory, planning conditions imposed on the developers ensured retention of the wet woodland habitat and its continued management for the snail. I’m not aware, however, of any monitoring of this private open space in the last 20 years. The paperwork for this should still be found on the planning archives of LB Richmond. In the late 1990s, when surveying redundant industrial docks opposite Lot’s Ait at TQ18137750 and so nearer to Amelia’s mooring , I found many live B. biplicata amongst the debris at the high tide mark. From the ease with which a search of the right habitat revealed the animal, my impression was that the rarity was at least partly the consequence of the not many people looking.



  2. Amelia on May 2019 at 5:27 pm

    Thank you for this information, what you say regarding Your search in the 90s was at that time true, however the last three years have seen a rapid decline. Yesterday The volunteer responsible for London wildlife trust Reserve at Isleworth ait and I spent the day walking and looking for Balea biplicata, none were found between Brentford along the Thames from dock Rd to Kew Bridge. We had a pretty thorough search at Ferry Quay steps In an area very close to Lots ait. From Kew bridge to Kew records office along the Thames four live specimens were found just outside St George’s snail reserve.
    Brentford ait and lots ait were not visited but need to be in light of total disappearance on Isleworth ait within the last three years. I believe Dukes meadows reserve in the Hounslow borough has a reported population.
    Amelia



  3. Kevin Garrett on May 2019 at 12:18 pm

    Amelia fascinating and brilliant what you are doing if you ever want someone to set up another breeding programe I would be more than glad to help…



  4. Mick Massie on June 2019 at 5:40 am

    I visited Dukes Hollow with the Rangers that manage Hounslow’s nature reserves in October last year (2018). Although it has been largely neglected over recent years, the Ranger team there are now sensitive to the fact that it needs some management. I worry that the combination of fly-tipping and the construction of the Thames Path walkway under Barnes Bridge will create too much disturbance. We found evidence of Alinda biplicata there in 2018, including these recent shells. https://flic.kr/p/2g78dmw and https://flic.kr/p/2g78cjN. I haven’t revisited this year, but will do later in the year.



  5. Amelia Stodel on June 2019 at 9:38 am

    Kevin Garrett on May 2019 at 12:18 pm
    Please pass my contact details to Kevin Garrett
    Regards Amelia



  6. Minhyuk Seo on June 2019 at 2:46 pm

    Hi Amelia, will do.



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