Kingston University Biodiversity Action Group

16-05-2014: Of eels and algae

Wednesday was a day for exploring the river, the lovely weather had the clouds of insects flying over the Hogsmill and the surrounding bridges for the majority of the day and students out in force enjoying the weather.

Joe explains how to wrangle small eels for monitoring

Wednesday was a day for exploring the river, the lovely weather had the clouds of insects flying over the Hogsmill and the surrounding bridges for the majority of the day and students out in force enjoying the weather.

We had our second eel monitoring training session of 2014. Joe was brilliantly animated showing us how to check the trap and telling us about the history of the European eel. About the drastic population declines and how the ZSL coordinated project has been monitoring eel rivers around the country.

Talking to the volunteers about the monitoring scheme
The nice thing about this project is the real time conservation benefits that link directly to the results we submit.

Project data has helped target areas for eel passes to be installed (structures that allow eels to climb over weirs). Our results this year will be crucial to assess the effectiveness of a pass installed last year.

We were also recruiting volunteers for our second Riverfly monitoring session which we hope to run later this year. 
Clouds of riverflies over the Hogsmill
This link will take you to the blog describing what we did on the last session. If you are interested in taking part please, email me on to register your interest (dates TBC).

While we were in the area, some of us went and did some maintenance at the naturalised bank by Knights Park.

Some of you may remember what it looked like before the project took action earlier this year and many of you helped in its transformation...

View up towards the green bridge by the Stanley Pickering Gallery showing the changes over time 

Marsh marigold in bloom
One iris lies on its side, having been uprooted through algal build-up and fast river flows 

Blanket weed (a type of filamentous algae) has really established in the planted area. In the right conditions in areas with high levels of nutrients, it can double in volume every 24 hours. Hopefully as our plants establish more, they will use up some of the nutrients, reducing the levels available for the blanket weed. 

A lot of the weed catches on the plants and builds up into long floating strands on either side of the plant. In fast high flows, the action of the water dragging on the weed is strong enough to uproot the planted iris. 

While our plants are establishing (yippy!), the bad news is that the Himalayan balsam (Impatiens gladulifera) has also found the embankment – highlighted in the second photo for those of you who haven’t been to one of our balsum bashes.
Targeting systems are a go!

We’ll have our first balsam bash on Wednesday the 4th June 2014 and the second along with the KUSU picnic a few weeks later. We will be targeting the balsam at Knights Park and Middle Mill, including the plant that has made it to our embankment.

To find out a bit more about what’s involved in balsam bashing have a look at last year’s work here . To volunteer for the  balsam bash and help us to control this invasive plant species which can dominate our shoreline habitats, please email:

Getting involved:
You can get involved in the balsam bash and regular algae cleans of the embankment by emailing

Apart from the algae and balsam, the other issue that does affect the site is litter.

The caretakers at the site have been doing a great job each morning, helping the biodiversity by picking out the litter that they can reach from the planted shelf, but they can only reach so, far. 

A lot of the litter gets blown in  (empty plastic glasses, glass bottles, used cigarette filters) or thrown in (food waste) off the terrace area. – if you use the terrace area a lot, please help us maintain the planted area wild for wildlife by: 
  • Clearing up your empties into the bins at all times:
    • Most of the rubbish like the plastic cups are light and gets blown into the river if left on the ground/on the boundary wall during the day, or over night.
    • If the bins are full please let the bar staff know.

  • Making sure that food isn't thrown into the river. 
    • There is plenty of healthy food for the baby ducks due to the large amounts of nutrients in the water which we know is there due to the large amounts of algal growth
    • Bread and other processed foods can cause more harm than good  when feed to ducks and other birds so help the wildlife by keeping our food out of the river. 

1 comment:

  1. Hooray, we've just had our first eel of the season, a little one measuring just 7.5cm!