Ranunculus… The Truth

[John Bailey]

A couple of days back, I went for one of the more enlightening meetings of my life at the Wye & Usk Foundation’s HQ in Talgarth. There is so much to be said about this couple of hours that I am still digesting it all, but at the very least I think I have an answer to the question of the ‘Missing Ranunculus Debate’ on the Wye. Simon Evans is now the driving force behind WUF, especially so I guess after the sad loss of Stephen Marsh Smith, and a force he certainly is. After two hours of his company, I really felt like I’d gone through two terms of Uni lectures, so hot was my pen, so befuddled my brain. But I think I “got” the ranunculus issue… this is all according to SE!!!

The WUF HQ in Talgarth​

Ranunculus on the Wye has served the river colossally for all our lives. It has been a habitat for smaller fish and fry, and for huge amounts of invertebrates, and it has also given the river structure, collected sediment, and acted as a massive filter bed. Sun and nutrients have long begun to produce algae by the start of May, BUT then the ranunculus has grown up and the blooms have been destroyed by the invertebrates within it. This year, and last, without the ranunculus, this algae has been a huge and well-publicized problem.

Where has the ranunculus gone then? Between October 2018 and February 2020, there were four 5 metre floods on the river, whereas you might expect ONE such deluge every twenty five years. To make matters worse, the flood in February ‘20 was a monster, the biggest in decades, if not centuries, and it ripped out most of any ranunculus left.

Come that spring, a very dry, hot May inhibited growth of what was left, and what did emerge was destroyed by the remnants of the swan population. (And canoeists I wonder, Simon?) In short, this was the perfect storm, as it were, and 97% of Wye ranunculus perished in the blink of an eye.

The future? Upland land use has to be reformed so more water can be held back there, rather than disgorging it unchecked into the headwaters. That’s for starters. More ideas to come… from you? From WUF? Let’s keep this going?

The post 'Ranunculus... The Truth' first appeared in Fishing Magic Magazine.

Continue reading...

 

[Bluenose]

Once waters become algae dominated it is very hard to restore them. That said, restoration won't happen by itself, simply because there are far too many nutrients in most waters, and the 'good' species will be outcompeted and fail to establish. Habitat restoration has to be encouraged, the habitats themselves have to be managed and 'built' in my opinion. They need to be given every opportunity to compete with the numerous algae and cyanobacteria species that thrive on excess nutrient.

The number of stillwaters that are now eutrophic is mind blowing, couple that with questionable fishery management and we are in the midst of an almost perfect storm where fisheries, algae, cyanobacteria and habitat loss is concerned.

 

[theartist]

I've been referring to the floods as a likely reason for the ranunculus disappearance on the Severn for quite a while now, I seem to recall it feel on deaf ears every time I mentioned it. It's amazing how few anglers care for the water weed, I'd say more curse it when fishing weedy venues which shows how backward the average angler has now become in coping with anything wild.

If it is flooding then could there be a systematic restoration of weedbeds by volunteers? I'm getting deja vu now as I seem to recall asking that question a while back too.

 

[John Aston]

Interesting. And it explains the loss of ranunculus on the Swale , which has had increasingly awful floods , but not on the Rye (in NE Yorkshire ) where rainfall is relatively low. I have racked my brains and cannot even guess the answer - some have suggested tree canopy and swans , neither of which stand up to any scrutiny . We've had no discernible pollution but we have experienced climatic change in the form of long cold springs and baking summers.

Any informed opinions ?

 

[John Aston]

Anybody ? Or is everybody groping in the dark ,as I am , for a reason to explain the disappearance ?