see:

Short Life of British Mayfly Halved by Climate Change

Very interesting reading

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What goes around comes around.

Jamie

This is all very interesting but I'm struggling to see how an increase in average water temperature of just 1 degree C can make the mayfly nymphal phase of the life cycle suddenly reduce from two years to one. In a spring fed river like the Dove the temperature is fairly constant so you can't really factor in higher peaks that comprise the average.

I think that scientists have got a lot about the mayfly wrong. The main thing is the theory that they live 24 hours as an adult because on that basis it's hard to explain the huge falls of spent that you sometimes see on the Irish lakes days after the last big hatch of drakes, especially when the weather has not been conducive to egg laying.

I spoke to Stuart Croft about this and he was certain that despite having no mouthparts the mayfly is able to absorb moisture through its body and stay alive for several days waiting for good conditions to return and lay eggs. The larger size of the danica might make this easier than for smaller ephemerids which are perhaps what we should be worrying about.

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“There is no more lovely country than Monmouthshire in early spring. Nowhere do the larks sing quite so passionately, as if somehow inspired by the Welsh themselves. There is a blackbird on every thorn and a cock chaffinch, a twink as they call him there, on every bush...... It moved me profoundly. I had been spared to see another spring, and I thank God for it.”

Oliver Kite
“A Spring Day on the Usk”
A Fisherman’s Diary

Thank you for that link it's gone in the mix.

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ランカシャー·ラッズの

Worth it just for the picture:

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