Wildlife Column with Prof Ian Rotherham

Andrew Crofts recently contacted me about a sighting on the River Don near Wharncliffe Side and concerned that, it was (if you excuse the pun), a little fishy.

Wednesday, 5th June 2019, 8:41 am
Updated Wednesday, 3rd July 2019, 4:40 pm
Sheffield weather expert Professor Ian Rotherham.

‘I hope you don’t mind my writing to you, but I am seeking some advice. I saw, last Saturday, on a stretch of the River Don at Wharncliffe Side, a dead fish.

This was the second time within two months and I started to think about who might be able to give me the advice I was looking for.

As you can see from the attached photographs, the fish is lying on its side and is not floating.

Dead salmon

The one I saw previous to this was a mere couple of yards upstream from this when I saw it and I guessed it may have been a predation death, or an old-age death.

I know salmon usually die after they have run upstream and spawned, but I assumed that they would be greatly thinned down and knocked about by that stage.

This doesn’t appear to be the case with these pictures. I can’t see any trauma damage, and I couldn’t in the previous one either.

It may be perfectly innocent, but perhaps you could advise as to whether or not someone should be informed.

I don’t know anything about fish pathology, or even the recognition of different fish species, but I am an enthusiastic observer of nature, and this doesn’t seem quite right.’

Well, I think I can allay Andrew’s fears and as he noted we have had fish-passes installed in the weirs downstream and so salmon can now migrate back to the traditional headwaters.

Indeed, this will be the first time for a few centuries that salmon have returned to spawn! I have heard of other dead salmon turning up this year and so they are back and at least attempting to spawn.

Some adults do attempt the return journey to the sea but in truth not many survive. Over the last 30 or 40 years the River Don has ‘rewilded’ and salmon have returned.

Professor Ian D. Rotherham, of Sheffield Hallam University, researcher, writer and broadcaster on wildlife and environmental issues.