Whether you are a boater, or an angler, this affects you! We are currently under attack from an imported plant that is trying to take over our waterways. We have a serious problem with Pennywort and duckweed. We need action, quickly.

Over recent years we have become used to seeing our inland waterways turned green by duckweed. This in itself is serious enough because it affects our ability to cruise the waterways without constantly having to empty the filters that strain the raw water that cools our engines. Although duckweed is a very small plant they reproduce very quickly and pile up on themselves very quickly. Animals have been lost because they mistake the weed for grass.

There is though, a new kid on the block now, the problem with Pennywort, a fairly new aggressive weed that is choking the waterways. The only action that I’m aware of carried out by Canal and River Trust is to push the weeds down the canal to a point where a lock connects to a tidal river. This cannot be the answer to what is a huge problem for boaters.

Far more dangerous is the outbreak of an epidemic of the plant pennywort. I first saw this weed on a boat trip to Goole in East Yorkshire on the Knottingley and Goole canal. It was novel to see, as the weed forms its own island system that floats on the surface and is propelled by slight currents and wind. I could see that the tentacles of the weed were fairly substantial, and as they are closely intertwined could cause a problem if fouling the propeller. As a matter of fact, the weed is capable, I believe, of growing 6 to 8 inches a day in the right conditions. This was 2 years ago.

This picture was taken in our marina 2 years ago in 2022

This picture was taken today. 2024

This picture, also taken today is the marina bay to our immediate left.

This is the problem with Pennywort, by this time next year the marina will be totally choked up if nothing is done.

So, who’s responsibility is it? What could have been done to prevent this situation? Who are going to be affected by this if nothing is done?

Canal and River Trust have the responsibility for these waterways. They are the ones exponentially raising costs for boaters. If they had acted two years ago to remove the relatively small amount of pennywort in the system this situation could have been completely avoided.

A fellow boater, now acting as spokesman for the rest of us with boats here, recently contacted C&RT to complain that having gone out sailing for the last time this season, struggled to get through the weed choking part of the marina. Further, after dodging mini islands of weed in the canal arrived at the lock west of the marina, only to find that the weed in the lock was preventing the lock gates from closing properly. He opened the lock paddles thinking the water pressure would crush the weed. It didn’t. He had to reopen the gates and flush the lock out before the lock was usable. It took ¾ of an hour. Unacceptable.

On his arrival back at the marina he had to struggle through the weed to manoeuvre into his mooring. He states that if the weed had stalled his engine, he would have been dead in the water. Not much of a problem in sight of his own mooring, but dangerous in the middle of nowhere. Cruisers don’t have weed hatches. The day after returning from his adventure he checked his raw water filter to find it almost full of chopped weed.

In his conversation with C&RT they tried to suggest that the problem with Pennywort and duckweed is the responsibility of the marina. This is utter rubbish. The Lily pads in the marina are a part of the flora of the marina, having been rooted there for decades.

The pennywort is an alien invader, having arrived here after travelling for miles through C&RT’s waterways. Part of their responsibility is to keep the waterways navigable. I’m aware that C&RT have been active in some parts of the system, but the actions they have taken have been after the fact. Early action is surely what they should have taken when the weed first appeared.

As it stands at present the waterways are navigable until an obstacle like a lock or similar stops the weed dead in the water. This leads to a massive build up of the weed that ends up inside the lock. If there is enough weed present it can, and does, prevent the smooth operation of the lock. When the lock has done its job, the weed that has been inside the lock continues on its merry way. On the weed’s journey it will pass marinas, and some of that weed will be blown into the marina.

Once inside the marina it breeds very quickly and will, eventually, block the marina. Small outboard engines will not be able to deal with the weed at all, while boats with larger engines will have blocked water filters and quite possibly, heavily fouled propellers.

The waterways are an attraction for the public and anglers. As it is, both of these groups are largely unaffected by the weed. Looking forward though, if the locks become inoperable through forced reduction of use, the weed will build up fast. We have all seen the massive collection of duckweed that forms in the summer months on sections of the cut. I have been at Keadby where no water was visible at all to the west of the lock gates.

As I write this, the nights are drawing in. Soon, there will be frosts that will kill the foliage of the Pennywort. The roots will remain viable and next year we’ll see an exponential explosion of growth.

This situation MUST be addressed if C&RT expect us to accept their massive increase in fees. There are already rumblings that do not bode well for C&RT.

Common sense in an old adage, ‘A stitch in time saves nine’. Please note……

If you want an update to the battle to rid what is known as ‘the worst aquatic weed in the UK’, take a look at this link, from DEFRA Department for Environment Food and Rural Affairs. Fascinating reading.  Killing Pennywort.

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