Tossing and turning in a scarlet sea, the dozens of pilot whales cannot escape the knife blows raining down. Driven into the shallows, where they are forced to bathe in the blood of their relatives and companions, their distress is palpable as hunters hack at their smooth sides.

Once they are dead — or, at least, dying — hooks and ropes haul their bodies ashore, where crowds of people, many of them children, have gathered to watch this bloodthirsty spectacle.

Tragically, the whales, the victims of this brutal human behaviour, are here as a result of their innate sense of loyalty. Such is their devotion to their extended family that if one member becomes stranded on land, the rest of the pod will remain with the stricken animal, even if they endanger themselves.

The Faroe Islands in the North Atlantic witnessed the latest grindadrap, or grind, this week (pictured)

It sees the islanders chase down a pod of pilot whales and force them onto the shore, where they are killed

But this same loyalty drives them all towards the lances that await them on the shore. The whales stick together, so they die together.

This week, the Faroe Islands in the North Atlantic witnessed the latest grindadrap, or grind, as these hunts are called.

A pod of whales was sighted off the islands and 25 boats set out in pursuit. In the course of two hours, the men herded the whales inshore and eventually caused something called — in a euphemism a politician would envy — an ‘assisted stranding’.

There, on Hvannasund Beach, the Faroese were waiting with their weapons. Of the 200 whales in the pod, 120 were killed.

Pause to consider pilot whales. With distinctive dome-shaped heads, they come in two species hard to tell apart, long-finned and short-finned, and they can be found just about anywhere in the ocean.

They are often collectively referred to as blackfish because of their colouring — although they are not fish but mammals like us. As whales go, they are not large; five metres is about the maximum length.

They are renowned for the intense and close nature of their society — unusually, females and males stay in the same group as their mothers. They display something close to grief when members of their pod die: pilot whales in the North Atlantic have been spotted forming a protective circle around one adult and a dead calf.

Certainly, they seem to have an emotional life. Volunteers who have helped them when they became stranded on Scottish beaches have talked of the creatures ‘following’ them with their eyes, and making plaintive cries. Remarkably, when they were in distress, the animals responded positively to female voices, particularly when the volunteers sang. They seemed to find the sounds soothing.

Observers have noted, too, that pilot whales seem to enjoy annoying sperm whales, bumping and nipping the huge yet timid animals for no discernible purpose.

These intelligent and curious animals are, like many whales and dolphins, very vocal. Early research revealed that pods — their large family groups — develop their own traditions, such as distinctive diets, even when several pods live in the same area, and unique calls. The newborns within a group soon learn to mimic their elders’ clicks and whistles.

This week 25 boats set out to chase the pod, forcing them on to Hvannasund Beach, where the Faroese were waiting with their weapons. Of the 200 whales in the pod, 120 were killed (pictured)

‘We suspect that these (observations) are the first visible tip of an iceberg of blackfish culture,’ wrote Hal Whitehead and Luke Rendell in The Cultural Lives Of Whales And Dolphins.

The culture of the Faroese people has long involved whaling. When the animals are sighted close to shore and conditions are calm enough, the call goes out — once by word of mouth, now by phone call and social media — and the islanders race to the water.

These grinds, as the pictures show, do not involve gentle euthanasia. Those taking part wield knives to kill the whales by severing their spinal cords and arteries. Later, it falls to the chief of police to share out the meat and blubber.

Over the past three centuries, the Faroese have taken an average of 838 pilot whales each year, according to a 2012 study.

But the Faroese — who are semi-autonomous from Denmark — get upset when outsiders criticise them. ‘Whaling is a natural part of Faroese life and pilot whale meat and blubber are a cherished supplement to households across the islands,’ said a spokesman for the Faroes, Pall Nolsoe.

It is a long tradition, certainly, but longevity does not excuse brutality. We in Britain once had long traditions of bear and bull baiting, of cockfighting and of public executions, but our society became more civilised and so abandoned such bloodthirsty pastimes.

But the Faroese, who are semi-autonomous from Denmark, insist what they are doing is legal and sustainable

There comes a point when some traditions can be set aside.

The Faroese claim that killing pilot whales is sustainable — their numbers are such that the deaths do not threaten the species — but that misses the point. Pilot whales may not be classed as endangered, but the slaughter of a large community of sentient beings does not seem to be justified by the argument that there are plenty more where they came from.

The Faroese also claim that this activity is wholly legal.

‘Whaling in the Faroe Islands is conducted in accordance with international law and globally recognised principles of sustainable development,’ Nolsoe said.

The law here is complicated. Falling whale numbers led to an international moratorium on whaling in 1986 — but the International Whaling Commission still allows some ‘subsistence’ whaling.

There is also disagreement about whether smaller whales, among them pilot whales, should be covered by the ban.

On the legality of their hunt, the islanders are challenged by the conservation organisation Sea Shepherd.

‘Pilot whaling is illegal. It is illegal in Europe, it’s illegal in Denmark, therefore it is illegal in the Faroe Islands. Denmark claims it is for the Faroe Islands to decide whether to stop whaling but this is not true,’ said Liesbeth Zegveld, lawyer for Sea Shepherd. She claims that Denmark has a legal duty to stop the whaling.

Activist group Sea Shepherd say it is not legal, and are preparing action against the Kingdom of Denmark to try to stop the killing (pictured in 2011)

The organisation is preparing to proceed against the Kingdom of Denmark, challenging the legality of hunting pilot whales. This represents a change of tactics: Sea Shepherd previously sent activists to disrupt hunts.

It is becoming a political issue. The mainland Danish government doesn’t want to alienate the Faroese but neither do they want a Europe-wide reputation for barbarism. If they can’t keep both sides sweet — and that looks increasingly unlikely — they will look in vain for a solution.

The Faroese are in other ways an extremely impressive people, independent-minded and tenacious of their culture.