Moby-Dick is on his last legs — or, rather, his fins. He’s keeled over in the water and is looking very unwell.

His tail’s had a chunk taken out of it, there are vicious slashes on his side and evidence of bruising.

But it’s not Captain Ahab that has done for this giant of a creature but Nature’s very own harpoons — the claws and razor-sharp teeth of a rampaging otter. And just like the other dozen or so fish it tore apart in my pond, I’m absolutely gutted.

It was a fortnight ago I sauntered out one Saturday morning to take a turn around the garden, enjoying that glorious colourful moment between summer’s end and the start of autumn when I saw it, a scene akin to a chainsaw massacre movie or some slasher series on Sky

I’m the first to admit that, as pets go, fish are not the most companionable. You can’t cuddle them, take them for a walk or watch them leap and catch a tennis ball in mid-air. You never get to love them like you do a dog or a cat.

But you can admire their grace, their colour, their beauty and their infinite variety as they glide aimlessly to and fro.

And I did, truly, appreciate all this from the day more than seven years ago now when I moved into my house in the country and inherited a sizeable outdoor pond with an array of bright goldfish, some secretive black tench, a shy brown trout — and a massive orange koi carp.

It was getting on for two feet long and at least 20 years old, probably more.

My two ghost koi were flat out on the side of the pond, lifeless, with huge rips in their gills and flanks. They’d been caught, landed, toyed with, nibbled and then just left. It seemed so utterly pointless a slaughter

Blimey, he’s a big ’un, was my instinctive reaction when I first saw him, and also of every visitor we ever had. He (or she, I’m not sure; how do you sex a fish?) was instantly named Moby-Dick.

I’d never had fish before, not a goldfish or even a stickleback in a jam jar as a kid.

How did one look after them? I quickly learned that if you feed them twice a day and keep the water clean and moving, they pretty well look after themselves.

Now we were a family that kept fish and I found I liked having them around. In moments of stress, I could take time away from the computer and be soothed by their serenity — especially Moby. He never moved at anything more than leisurely pace, as if there was nothing to get het up about or hurry for. Which, in his watery world, there wasn’t.

I decided to get him some companions — a couple of silver ghost koi that would grow to a similar size — and he didn’t seem to mind. They all fitted in around each other. So did the comets with their flowing fantails and the pink-tinted shubunkins with streaks of blue.

The palette of colours was a treat, like your very own Renoir in the back garden but constantly on the move and shifting shape.

Nor were the fish totally clueless and unresponsive. They took to lurking beneath the conservatory window from which I fed them every day at a certain time, waiting to tuck in.

There were occasional casualties, including a brush with a hungry heron which led to us cover the pond with netting. But, by and large, they all cruised serenely on. Until . . .

I’d understand if they’d been eaten down to the bone — destroyed so another creature could feed and live. But this was like foxes wantonly biting off the heads of chickens, killer whales toying with baby seals or a cat with a mouse — pure savagery

It was a fortnight ago that I sauntered out one Saturday morning to take a turn around the garden, enjoying that glorious colourful moment between summer’s end and the start of autumn when the air is suddenly crisper. Everything was as it should be — and then I saw it, a scene akin to a chainsaw massacre movie or some slasher series on Sky. I really did cry out in horror.

The two ghost koi were flat out on the side of the pond, lifeless, with huge rips in their gills and flanks. They’d been caught, landed, toyed with, nibbled and then just left. It seemed so utterly pointless a slaughter.

I’d understand if they’d been eaten down to the bone — destroyed so another creature could feed and live. But this was like foxes wantonly biting off the heads of chickens, killer whales toying with baby seals or a cat with a mouse — pure savagery.

And it didn’t stop with the koi. We discovered more half-chewed carcasses discarded in the undergrowth. The waters of the pond were deathly still, what fish remained congregated in the depths somewhere.

And it didn’t stop with the koi. We discovered more half-chewed carcasses discarded in the undergrowth. The waters of the pond were deathly still, what fish remained congregated in the depths somewhere

Only Moby-Dick was visible, his streamlined body barely moving, shocked into immobility.

The culprit? We back on to woodland, the river and the sea are just a mile or so away. So the chief suspect had to be an otter. I shivered at the thought of it marauding underwater, all teeth and claws, terrifying my family of fish that had nowhere to hide, as they would in a river or a stream.

Now, the Tarka in me has always been taken with otters. They’re delightful, engaging, elusive creatures, rarely seen. I’ve spotted them in remote places, in the sea off a Hebridean island, and once I watched a mother followed by five kittens traipsing in a line across the rocks. It was thrilling, a once-in-a-lifetime sight.

Except now there was one in my own back garden, casually dishing out death.

The culprit? The chief suspect had to be an otter. I shivered at the thought of it marauding underwater, all teeth and claws, terrifying my family of fish that had nowhere to hide, as they would in a river or a stream

I consulted the internet on what to do. I searched ‘protection from otters’ and screeds came up . . . about the protection of otters!

You can’t hunt, capture, kill, or even disturb them, on pain of imprisonment. You can say boo to a goose but I’m not sure you can even give an otter a withering look without running foul of the law.

It is, of course, understandable. In the years following the industrial revolution, the otter population in Western Europe declined by 95 per cent. In Britain, the numbers fell dramatically in the Fifties and Sixties, due to loss of habitation, pesticides and industrial chemicals in waterways, and to hunting — often to protect fish stock and game birds — which wasn’t banned until 1978.

Now, as water quality in our rivers and streams has improved dramatically, with a consequent increase in fish, their food source, they’re back and thriving — with a vengeance.

I consulted the internet on what to do. I searched ‘protection from otters’ and screeds came up . . . about the protection of otters!

And I’m not alone. Pond owners around the country are reporting their losses. In Burbage, Wiltshire, Mike Tupman lost four koi carp worth £2,500 to otters. In nearby Westbury, Trevor Weaire lost 33 of 34 fish. ‘The otters ate the livers and left the rest,’ he told a local paper. They’re also partial to the kidneys, apparently.

As far as I’m concerned, there is at least one too many otters in my patch now. Otter fans will undoubtedly throw up their hands in horror at such a suggestion. They think them cute, playful and lovable creatures and point out that as a species they’ve been around for millions of years.

Well, so, dammit, have fish. Don’t they have any rights?

Apparently not. I was helpless when it came to protecting mine. The first night after the massacre we made a valiant effort, barricading the garden gates and switching on outside lights to ward them off.

All to no avail. The next morning there were more lacerated corpses strewn around the pond. Only Moby remained, half his magnificent tail gone, listless but clinging on.

You can’t hunt, capture, kill, or even disturb them, on pain of imprisonment. You can say boo to a goose but I’m not sure you can even give an otter a withering look without running foul of the law

And now we knew for sure it was an otter that had done the damage, rather than the other possibility, a mink. It was caught on a night-sight camera a friend rigged up — long neck and tail, squirming through the bars of the iron gate as bold as brass,.

A female apparently and youngish, a teenager out on a spree for a nosh-up and some fun.

And at my expense! Those two ghost koi I’d bought were 18 in long, a couple of pounds in weight and worth several hundred quid each if I’d ever wanted to sell them. Now they are just ghosts.

The otter hasn’t returned as far as I know. No point really. Nothing much left to get her teeth into — just a wounded and clearly traumatised Moby.

I asked an expert if there was anything I could do to save him but there isn’t. If I hoik him out in a net for treatment, the shock would probably kill him anyway.

Pond owners around the country are reporting their losses. In Burbage, Wiltshire, Mike Tupman lost four koi carp worth £2,500 to otters. In nearby Westbury, Trevor Weaire lost 33 of 34 fish. ‘The otters ate the livers and left the rest,’ he told a local paper

Let Nature take its course. As if Nature, ‘red in tooth and claw,’ as Tennyson put it, hadn’t done enough damage already.

I am not sure where we go from here. The pond is achingly empty, just a sad, lifeless water feature now. But I’m reluctant to re-stock it and then have the same thing happen again. I bet otters have good memories. Another whiff of my fish and she’ll be back.

So I reckon I’ll leave it until the spring. Outdoor fish pretty well hibernate in the winter anyway, falling into a stupor when the water temperature drops below 10C and barely moving until it warms up and they start to feed again. I’ll think about it then. I’ll also do a bit more research into how to keep otters out. If my heart’s still in it.

STOP PRESS: Moby-Dick didn’t make it. I’ve just had a look and he’s floating on his side, his gills not moving. He’s dead. We hauled him out with difficulty — gosh, he was heavy — and laid him out on the lawn for our farewells.

I couldn’t believe how sad I felt. We couldn’t bury him — the foxes would have dug him up. So it was into a black plastic bag. But which bin do you put a dead koi in? Definitely not the recycling one.