Category Archives: Chalk stream restoration

This week’s Ecological surveys

This week has been a busy one for surveying ecology on the stream and pond.

On Wednesday evening Louise and Anna did an informal bat survey. As it began to get dark, the bats emerged: Common and Soprano Pipistrelles were plentiful along the stream and a Daubenton was very active over the pond at the allotments. Noctule and brown-long eared bats were also possibly detected – further survey work will be needed to confirm their presence.

[Update: with the help of volunteers from Kent Bat Group, further bat surveying was undertaken in September 2021. Common, Soprano and Nathusius’ Pipistrelles, along with Daubenton, Noctule and (very likely) Brown Long- Eared were detected. Bats are indicator species and the presence of so many varied bats along the stream is very exciting and a really good sign of the health of the Westbrook! The survey results can be found here.]

On Thursday afternoon, Bob Gomes carried out an aquatic invertebrate survey on the Westbrook (at West Street Bridge and Chart Mills) – to supplement the one he conducted last summer. David assisted and Anna looked on as a whole host of invertebrates were found including worms, flatworms, leeches, water mites, caddisfly larvae, snails, gammarus and beetles . More detail and a comparison with the survey last year and implications for the management of the stream will follow, but as we found last year more interest was found in the gravel areas than the silty ones. This suggests that our work to scour the silt and increase the gravels along the stream is the right one. Thanks very much to Bob for doing this survey again.

Life below the surface – A stream teeming with life, by Bob Gomes

Life below the surface – A stream teeming with life

In August Anna, David and I undertook a preliminary survey to investigate the animal life living within the stream at three sites between the West Street bridge and Chart Mill.  A short report on our finds will be produced this Autumn but I thought members might be interested in seeing photographs of some of the creatures that were revealed by the sampling technique. At first sight, many of the small invertebrates look rather nondescript but close up views reveal their true intricate beauty. Even leeches and the flatworms, looking like aliens from outer space, are truly colourful.

The most abundant animals were small crustaceans, the amphipod (body flattened from side to side or laterally compressed) Freshwater Shrimp Gammarus pulex  and the isopod ( body flattened dorso ventrally ( body flattened from top to bottom)) Water Louse Asellus aquaticus. Water lice are very common in slow flowing waters where they live amongst the bottom debri or slowly crawl up water plants. The freshwater shrimp inhabit waters with abundant dissolved oxygen and a high lime content. They usually swim on their sides and are very active and commonly found on stones or bricks on the stream bottom. Both are abundant in the stream where they feed on organic matter within the silt. Plenty of that within the stream!

The tangle of watercress provides a refuge for small fish such as the Ten-spined Stickleback. The number of spines on its back varies from seven to twelve and it is sometimes also called the Nine-spined Stickleback. It prefers slow flowing or still water and can tolerate slightly brackish water. It is present in good numbers wherever there are beds of watercress. The Fish Leech illustrated lives free amongst water plants and is a common external parasite of fishes. It will prey on Sticklebacks by sucking their blood. The specimen photographed was just 15 mm in length but it can grow up to 25 mm. It has prominent suckers at both ends of its body and is a good swimmer. When not active it adopts a fishing posture while attached to a water plant. I was amazed by the pattern of the pigmented rays on the rear sucker when I looked and photographed it through the microscope.

The other leech illustrated (Glossiphonia complanata) is not so mobile as the Fish Leech and moves in a typical looping leech manner. It is rather rubbery in consistency and rolls into a lump when disturbed. The black dots at the front end are three pairs of eyes. It is sometimes called the snail leech because if feed on the body fluid of snails as well as other invertebrates. It grows up to 30 mm in length.

Looking a bit leech like are the flatworms but they glide over the surface rather than loop along. The two species photographed the milky  white-bodied Dendrocoelum lacteum with its digestive system showing through the body wall  and the darker Dugesia sp probably lugubris.
The former preys on water lice and the latter will feed on water snails. They are largely nocturnal and in the daytime are usually found under stones or on the underside of leaves looking like lumps of jelly. Their mouths are not at the front end but on the underside in the middle of the body!

Pond snails are abundant on the water cress. The Wandering Snail Radix (Lymnaea) peregra is probably the commonest water snail in Europe found in a wide variety of habitats from lowland ponds to mountain streams according to the Collins Field Guide. Note the eyes at the base of the tentacles. The other similarly shaped snail but coiling in the opposite direction (sinistrally) and with more pointed tentacles is the Bladder Snail Physa fontinalis. When expanded the fleshy body lobes – mantle – wrap around the outside of the snail. The flattened tightly amber snails with tight whorls belong to the genus Planorbis. The specimens photographed were just 5 – 8 mm in diameter, but the largest of the genus  can be up to 35 mm in diameter. The common name for the group is Ramshorn snails. I have tentatively identified three species living in the stream.

Many insects depend on the stream for various stages of their life cycle. A couple are illustrated. The larva of a small midge, the Meniscus midge, Dixa sp. with its body characteristically bent sideways into a U shape and the Black Fly larva Simulium. The adults of the Black Fly are notorius biters of humans and other animals. The Black fly larvae attach themselves by small hooks at the swollen rear end to  a web, woven onto stones. The front end – shown in close up – bears two moveable fans of bristles for catching food. They are common in flowing water and the specimens we found were at the Chart Mill site where the water is fast moving over a stony stream bed. We also found non case bearing Caddis fly larvae at this site.

The photographs illustrate just a few of the animals discovered in the stream, so give a thought to all that life when you are next moving the watercress! Pushing the cress to one side does give the majority of the animal life a chance of moving back into the water.

The full report can be found here:

Westbrook Aquatic Invertebrate Survey Gomes Summer 2020

All photos taken and supplied by Bob Gomes

Low flow channel installation continues – Sunday, 26th January, 10am-1pm

The next phase of the low flow channel installation work will take place on Sunday, 26th January, 2020. We will be continuing to install faggot bundles into the stream with the aim of naturally narrowing it and creating more diversity in stream flow and habitat.

We will start at 10am and work until around 1pm.

Our site this time will be behind Stonebridge Way and we will meet at 10am near the footbridge between The Knole and Beech Close.

Please bring a drink and a snack for yourself along with strong gloves (waterproof if possible) and wellingtons, waders, loppers etc if your have them. Please name any equipment you bring.

Everyone is welcome and, of course, we look forward to seeing new faces too.

Next phase of Chalk Stream Restoration – Saturday 27th April – 10am to 2pm

The next phase of the chalk stream restoration work will take place on Saturday, 27th April. We will be installing faggot bundles into the stream with the aim of naturally narrowing it and creating more diversity in stream flow and habitat.
We will be working again with the Mark Gallant of the North West Kent Countryside Partnership and will start at 10am and work until around 2pm.
Our site this time will be behind the Catholic Church on Tanners Street. Please meet at 46 Tanners Street, Faversham at 10am, to help collect bundles and stakes before we move onto the site. Please come through the double gates to the side of the building.
Please bring a drink and a packed lunch for yourself along with strong gloves (waterproof if possible) and wellingtons, waders, loppers etc if your have them. Please name any equipment you bring.
Everyone is welcome and, of course, we look forward to seeing new faces too.
Thank you!
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Dog inspecting the just-delivered hazel bundles

Thank you for all your hard work

Thank you to everyone who came along on Saturday to help install the next phase of the low-flow channel downstream of the footbridge between The Knole and Beech Close. It was a day of hard work, but was very successful, as these photos demonstrate….

THE STREAM A FEW DAYS BEFORE THE WORKS:

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LOADING THE BUNDLES ONTO MARK’S PICK UP:

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THE BRIEFING:

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LAYING OUT THE BUNDLES:

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CUTTING THE STAKES TO SIZE:

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HAMMERING THE STAKES IN – PARTICULARLY HARD WORK!:

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WORKS COMPLETE (FOR THE DAY) – THE LOW FLOW CHANNEL SUCCESSFULLY INSTALLED:

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THE SITE NOTICE EXPLAINING WHAT WE’VE DONE:

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Creating a ‘low-flow’ channel – UPDATE!

Further to my post last week (in italics below) about the installation of a low flow channel near the West Street Bridge a few things have happened…

The story is fairly complicated but the upshot is that due to local issues around surface water and sewage flooding around Tanners Street, Southern Water have decided to do some investigations of the local drainage network. This could include the Westbrook. While our planned works are consented, after discussions with KCC (the lead local flood authority), Swale Borough Council and the Lower Medway Internal Drainage Board, it has been decided to postpone the installation of the low-flow channel near the West Street bridge until more is understood about the drainage situation around Tanners Street.

As a result, on Saturday, instead of working at West Street, we will be concentrating on the installation of the low-flow channel downstream of the works started in July 2017 – at the footbridge between The Knole and Beech Close. If you would like to join the work party doing this work, please contact us via this website.

Thank you everyone!

On Saturday 17th November 2018, the Friends of the Westbrook and Stonebridge Pond, supported by the North West Kent Countryside Partnership, will continue the process of installing a series of stakes and bundles of thin chestnut branches into this section of the Westbrook, working upstream from West Street.

The aim of this work is to create a gently curving ‘low flow channel’. In times of low water flow (most of the time these days) the stream’s flow will be concentrated in the narrow section between the bundles with the aim of scouring the stream bed and exposing the natural chalk and gravel which line the bed. Over time, this should look better than the brown silted stream bed and will create a more diverse and improved environment for invertebrates and fish which, in turn, ducks and birds feed on.

In times of high flow, water will fill the stream channel and the areas behind the bundles will silt up. In the spring these areas will be planted with native species such as yellow flag iris, marsh marigolds, water forget-me-not and water veronica.

This work has been consented by the Lower Medway Internal Drainage Board (LMIDB) and importantly is not deemed to increase the risk of flooding. The Friends of the Westbrook are supported by the Medway Swale Estuary Partnership, theMedway Valley Countryside Partnership (who drew up the plans for this work and obtained consent from the LMIDB), Swale Borough Council and The Environment Agency.