The price of tidal power

When did it become OK to save our wildlife at the expense of everyone else’s?

There’s no joy in it but it’s got to be done. We have to press ahead with harvesting the tidal energy of the River Severn, despite the havoc it is likely to wreak on local wildlife, because these days there is no such thing as local wildlife.

When we talk about living in a globalised world, we don’t usually think about nations sharing wildlife. But we are now getting other people’s fish. Bluefin tuna and anchovies are increasingly common in British waters and no doubt we’ll be getting into fights with foreign fishing fleets about them soon. Elsewhere, species of Japanese coral are migrating northwards. A few weeks ago, Australian scientists issued a report into the ocean biodiversity in their region. Rather shockingly, their tropical fish are moving away – those that aren’t dying off in the rapidly warming water are migrating southwards, following the plankton that are being carried on currents that are rising in strength.

You won’t be surprised to hear that the blame for all this flux lies with global warming. Rising temperatures leave the inhabitants of the ocean no choice but to embrace change. Paradoxically, though, taking measures to combat global warming – such as building the Severn barrage to reduce our dependence on fossil fuels – will also force changes on the natural world. It’s now a question of whether we value our creatures more than everyone else’s.

The Severn provides Britain with a golden opportunity to exploit lunar power. The moon’s pull causes earth’s water to bulge out from the surface and the geometry of the Severn creates a bigger bulge than most. The difference between its high and low tide is the second largest in the world; only Canada’s Bay of Fundy can beat the Severn’s 14-metre pile of water.

Hold that heap of water back until just the right moment and the resulting torrent on release is a renewable source of energy. A Severn barrage would provide enough lunar electricity to power 5 per cent of Britain’s homes, equivalent to three nuclear or gas-fuelled power stations. It would also last three times longer – at least. According to projections, the barrage could operate for over a century, compared to the few decades of lifetime offered by a nuclear plant.

A cross-party group of MPs is backing a campaign for the barrage to be built and David Cameron has recently instructed the Energy Secretary, Ed Davey, to look at the proposal. It still might not take off, however. That is because, from a local perspective, it will be an environmental tragedy.

As with any hydroelectric project, holding back the water floods areas that would usually be dry. In the case of the Severn barrage, many of those areas are mudflats designated as sites of special scientific interest: feeding grounds for important bird species. It’s also worth mentioning that forcing the water through electricity-generating turbines at high pressure cannot help but hurt fish populations, too.

No pain, no gain

The consortium looking to build the barrage has come up with a design that, it claims, reduces mudflat loss by 60 per cent and operates at lower pressures, easing the toll on the Severn’s fish. Perhaps there are other mitigation efforts that can be made, such as constructing artificial mudflats at the water’s new edge. Either way, it is hard to see how we can justify holding back the barrage now. We will have to sacrifice some of our cherished natural environment.

As far as carbon-free, sustainable energy generation goes, this is the low-hanging fruit. If we don’t grab it, our continued emissions will have a similar, maybe greater, impact on biodiversity in other places. Yes, it will hurt but when did it become OK to save our wildlife at the expense of everyone else’s?

 

Surfers ride the Severn Bore along the River Severn. Photograph: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

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A swimming pool and a bleeding toe put my medical competency in doubt

Doctors are used to contending with Google. Sometimes the search engine wins. 

The brutal heatwave affecting southern Europe this summer has become known among locals as “Lucifer”. Having just returned from Italy, I fully understand the nickname. An early excursion caused the beginnings of sunstroke, so we abandoned plans to explore the cultural heritage of the Amalfi region and strayed no further than five metres from the hotel pool for the rest of the week.

The children were delighted, particularly my 12-year-old stepdaughter, Gracie, who proceeded to spend hours at a time playing in the water. Towelling herself after one long session, she noticed something odd.

“What’s happened there?” she asked, holding her foot aloft in front of my face.

I inspected the proffered appendage: on the underside of her big toe was an oblong area of glistening red flesh that looked like a chunk of raw steak.

“Did you injure it?”

She shook her head. “It doesn’t hurt at all.”

I shrugged and said she must have grazed it. She wasn’t convinced, pointing out that she would remember if she had done that. She has great faith in plasters, though, and once it was dressed she forgot all about it. I dismissed it, too, assuming it was one of those things.

By the end of the next day, the pulp on the underside of all of her toes looked the same. As the doctor in the family, I felt under some pressure to come up with an explanation. I made up something about burns from the hot paving slabs around the pool. Gracie didn’t say as much, but her look suggested a dawning scepticism over my claims to hold a medical degree.

The next day, Gracie and her new-found holiday playmate, Eve, abruptly terminated a marathon piggy-in-the-middle session in the pool with Eve’s dad. “Our feet are bleeding,” they announced, somewhat incredulously. Sure enough, bright-red blood was flowing, apparently painlessly, from the bottoms of their big toes.

Doctors are used to contending with Google. Often, what patients discover on the internet causes them undue alarm, and our role is to provide context and reassurance. But not infrequently, people come across information that outstrips our knowledge. On my return from our room with fresh supplies of plasters, my wife looked up from her sun lounger with an air of quiet amusement.

“It’s called ‘pool toe’,” she said, handing me her iPhone. The page she had tracked down described the girls’ situation exactly: friction burns, most commonly seen in children, caused by repetitive hopping about on the abrasive floors of swimming pools. Doctors practising in hot countries must see it all the time. I doubt it presents often to British GPs.

I remained puzzled about the lack of pain. The injuries looked bad, but neither Gracie nor Eve was particularly bothered. Here the internet drew a blank, but I suspect it has to do with the “pruning” of our skin that we’re all familiar with after a soak in the bath. This only occurs over the pulps of our fingers and toes. It was once thought to be caused by water diffusing into skin cells, making them swell, but the truth is far more fascinating.

The wrinkling is an active process, triggered by immersion, in which the blood supply to the pulp regions is switched off, causing the skin there to shrink and pucker. This creates the biological equivalent of tyre treads on our fingers and toes and markedly improves our grip – of great evolutionary advantage when grasping slippery fish in a river, or if trying to maintain balance on slick wet rocks.

The flip side of this is much greater friction, leading to abrasion of the skin through repeated micro-trauma. And the lack of blood flow causes nerves to shut down, depriving us of the pain that would otherwise alert us to the ongoing tissue damage. An adaptation that helped our ancestors hunt in rivers proves considerably less use on a modern summer holiday.

I may not have seen much of the local heritage, but the trip to Italy taught me something new all the same. 

This article first appeared in the 17 August 2017 issue of the New Statesman, Trump goes nuclear