Posted by: lensweb | January 31, 2017

Why has the Canal Turned Pink?

canal-memeThe water has turned pink due to the presence of water fern, Azolla filiculoides on the Nottingham Canal near Cossall.  This Invasive Non-native species is currently choking the section of canal and this will cause problems for wildlife and users of the canal along this important piece of habitat.


In 2012 the Nottinghamshire Biodiversity Action Group, a partnership of voluntary, statutory and community groups working together to conserve and enhance the wildlife of Nottinghamshire to the benefit of people, were able to support the Canal and Rivers Trust (CRT) with advice and a small grant to tackle the water fern that at the time was present in the Erewash Canal and also in the Beeston canal.  As a result of this early intervention the sections of azolla on the Erewash canal (between Long Eaton and Stanton Gate have largely been suppressed) and the population on the Beeston canal eradicated.

It is intended to follow a similar methodology to try to prevent the spread and ultimately control the levels of Azolla on the Nottingham Canal.

The control method involves the introduction of the Azolla Weevil to the water body and the weevils then eat the plant and suppress its growth accordingly.  As the plant matter increases the population of the weevil increases, when the plant matter dies down the weevil population decreases in responses. On the Erewash canal, it is thought that CRT added so many weevils to the azolla that they managed to damage it so much that it was eradicated from the water body in one year.

To find out more about the weevil, the research that has been undertaken into its release in the wild and any potential impact on other species/habitats (the weevil solely eats Azolla and as such its impact on the wider environment is neutral), please follow this link to the CABI website. CABI (Centre for Agriculture and Biosciences International) is an international not-for-profit organization that improves people’s lives worldwide by providing information and applying scientific expertise to solve problems in agriculture and the environment.

Broxtowe BC, advised by Chris Jackson of Nottingham BAG, intend to  try out the azolla weevil in spring. If you are passing the Nottingham Canal after that time, check out the colour of the water to see if the weevils have restored the balance of nature.

Marion Bryce 31 January 2017



%d bloggers like this: