Tag Archives: ZSL

Volunteers Join Forces for the Hogsmill

The Hogsmill river doesn’t know how lucky it is!

Last week, 30 volunteers joined SERT and ZSL at London Zoo for the 2017 Hogsmill Forum.

2017_hogsmill_forum_ZSL

The Forum is an opportunity for us and ZSL to say thank you to all the volunteers who help us with our projects on the Hogsmill – Pollution Patrol and the Riverfly Monitoring Initiative.

It is also a chance to share wider plans for the river with the local community,  discussing ideas and actions for the coming year; all of which feed in to the Hogsmill Catchment Partnership which SERT host.

If you are interested in either project, get in touch – volunteering@southeastriverstrust.org

And why not have a read of these presentations which our speakers delivered through the course of the day?

Presentations:

Many thanks to ZSL for hosting us, and for letting us have a look around the zoo after the meeting!

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Eel Passage on the Hogsmill

During the summer a collaborative project between Zoological Society of London (ZSL), Surrey Wildlife Trust Kingston Group and the South East Rivers Trust (SERT) was undertaken to improve elver and eel passage on one of the lower weirs of the Hogsmill, the Clattern Bridge weir.

The European eel is a critically endangered species and needs all the help we can give it.  Pollution, overfishing, global warming, disease and habitat loss have all contributed to the demise of this charismatic species. The eel has a fascinating and mysterious life cycle in which it starts life in the Sargasso sea as a larvae, migrates across the oceans via currents to European rivers, metamorphosing a couple of times on the way to become glass eels and then elvers.

Once in rivers, such as the Thames and the Hogsmill, they migrate upstream to find habitat in which to grow and develop into yellow eels. After 5-20 years of life in rivers like as the Hogsmill they metamorphose again into silver eels and travel back to the Sargasso Sea to complete their life cycle.  Weirs and habitat loss in our rivers are factors that cause issues for eels and stop their upstream migration to suitable habitat.

This project involved installing plastic tiles covered in regularly spaced plastic protrusions onto the weir face.  The weir at Clattern Bridge is smooth and has shallow fast water flowing over it.  The tiles allow eels to wriggle up the weir and into the river upstream enabling them to carry on their migration. Eels are not very good swimmers compared to other fish and prefer to ‘wriggle’ so increasing friction in this way is ideal for them!

Below is a great video of eels using a similar design on the Wandle:

Armed with a couple of battery drills, some long drill bits and various stainless steel fixings we attached a continuous line of tiles to the weir surface.

eels1

It was a lovely sunny day and perfect for a day in the river!

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A big thanks to the Kingston local branch of SWT who provided funding for materials, drill bits and fixings and to ZSL for supplying manpower and eel tiles.

Elvers migrate upstream between April-September and so we are hoping they will appreciate our efforts when they arrive in 2017!

Author: Tim Longstaff

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Outfall Safari on the Hogsmill

ZSL and the Hogsmill Partnership are looking for volunteers to help us map polluted outfalls on the Hogsmill this October.

While walking the Hogsmill you may have noticed all the different pipes that can be found along the river bank. These pipes are usually part of our surface water infrastructure, transporting clean water from our roads and roofs into the river. However in some cases, these pipes or outfalls can be polluting the Hogsmill as they have been misconnected.

Polluted Outfall

Misconnections are a BIG issue for urban rivers and the Hogsmill Catchment Partnership have been working hard to start addressing this on the Hogsmill River.

A misconnection is when a toilet or washing machine has been connected to the surface water drain heading straight to the river, instead of the sewer system. You can read more about misconnections at on the Connect Right website.

Connect Right

This October, ZSL are running an Outfall Safari to map all these pipes heading into the Hogsmill, and assessing their condition to check for misconnections.

Volunteers will receive training on how to recognise signs of pollution at these outfalls and record the pipes on a new smartphone app. This survey data will greatly improve our understanding of the river system and help to target sources of pollution.

Interested?

If you would like to join the team, you can sign up on EventBrite to register your interest. Once you’ve registered, more information will be sent to you about where and when the training sessions will take place.

Sign Me Up!

For more information contact by email: Joe.Pecorelli@ZSL.org, or phone: 07974 725 557
Outfall BannerPlease register your interest to help at: hogsmilloutfalls.eventbrite.co.uk

You’ll need to read this before your training session: 2016-Pre-training-information-for-Hogsmill-Outfall-Safari-Volunteers..pdf

The 2016 Hogsmill Forum

The Hogsmill River may have its problems, but it is one of the lucky urban rivers to have huge community support and many enthusiastic volunteers.

We run our Pollution Patrol on the Hogsmill, tracking down polluted outfalls and misconnections. While ZSL run the Riverfly Monitoring Initiative which uses the kick sampling of invertebrates to check for organic pollution.

So to thank everyone for their hard work, both projects combined for a joint Hogsmill Forum – kindly hosted by ZSL at London Zoo.

Hogs Forum

The event was a huge success with some really interesting discussions on the priorities for the Hogsmill going forward. Below you can download PDFs of the presentations.

Presentations:

 

Polluted Outfalls and Riverfly Monitoring

Last week I was lucky enough to visit the Hogsmill River twice with some of our dedicated Pollution Patrol volunteers.

The Team!

From left to right: Geoff, Me (Polly), Steph, Peter, Bill and Jan

Our Pollution Assessment Volunteers (PAVs) work hard to track down and monitor polluted outfalls on the river, sending reports to the Environment Agency for action.

On Wednesday we were joined at a particularly bad outfall by our local Environment Agency Officer Steph to take some samples.

Sewage Fungus

Sewage fungus at the outfall

Steph sampled for ammonia, which is used as an indicator of raw sewage entering the river, and for oxygen available to river invertebrates and fish. Oxygen is a good indicator of how polluted an outfall is, as bacteria use up oxygen to break down organic pollutants, which reduces oxygen available to other species which can sometimes result in fish kills.

Sampling for Oxygen

For this week, both readings were fine.

This is one of many outfalls we’ve been looking at. You can find Steph’s updated report here.

Hogsmill Report July 2015

On Friday I was invited along to the monthly Riverfly Monitoring session at the same outfall with the same dedicated team. Every month they get together at this location and take a kick sample of invertebrates as an indicator of how healthy the area is.

Riverfly Monitoring

Some invertebrates such as caddis flies are very sensitive to pollution and are therefore an excellent indicator of water quality. If this is something you might be interested in, check out the website here!

Thank you to all our volunteers working on the Pollution Patrol scheme – we are making progress!

Continued effort at making the Hogsmill a little more welcoming for eels

A joint effort between the Zoological Society of London (ZSL), the Thames Anglers Conservancy (TAC) and South East Rivers Trust continued the ongoing efforts to assist elvers/eels with the final stages of their long 3500 mile migration from the Sargasso Sea up into the Hogsmill catchment. In August last year, the same partners installed an eel pass onto the most downstream obstruction in the catchment at Clattern Bridge, Kingston, which showed immediate signs of success with the first elvers ever being recorded further upstream at the ZSL eel monitoring site the following week.

Upstream of Clattern Bridge the next obstacle, the Environment Agency’s gauging weir, has already an eel pass installed for several years and so this time we turned out attention to the next weir upstream. Although a few incredibly determined eels have successfully made it past this obstacle, the weir  does without doubt prove to be the end of the line for many. With its vertical face, smooth sloping concrete surface and fast flows, the elvers generally have little chance of clinging on and and making it to the calm of the river bed upstream.

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The sloping weir with vertical face

In order to provide purchase and slower the flows, yesterday eel tiles were installed to the weir, guiding them in at the downstream end, helping them up and over and feeding them safely into the slack water at the bed upstream. A custom built debris deflector  and bracket to mount the tiles to the wall adjacent to the vertical face were manufactured by Norm Fairey, our regular go-to handy man.

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Eel tiles fixed to the concrete slope

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Vertical tiles to help the eels over the weir crest

Once completed we wandered down to have a look at the eel pass on the gauging station. It appears that the brush material makes a perfect media for plants to establish in, especially our arch nemesis Himalayan balsam. Concerned that the root network would be clogging the pass we set about unbolting it from the wall.

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Is it an eel pass or a hanging basket?

What we found was a densely matted root system which would have prevented even the smallest elver from getting through. Each section of the pass was removed, cleared and reattached ready for the first visitor to utilise. On the whole a very satisfying day.

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No way through!

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All clear and ready for the first migratory visitor

It will be interesting to see the effects that these actions will have on this years monitoring undertaken by ZSL and the keen volunteers. We will keep you posted with any news. This project was funded by Defra through the Catchment Restoration Fund.

A big thanks to David Harvey and Neil Depledge from TAC and Joe Pecorelli from ZSL. 

To see updates from the Wandle, please check out the website