CBRN / HazMat Training Blog

Gruinard Island and the Dark Harvest Commandos

Written by Steven Pike on 26 June 2024


Decades of secrecy shrouded Gruinard Island, laying off the western coast of Scotland. The island was deemed too dangerous to allow public access after it was contaminated during World War Two germ warfare experiments. In 1981, an unknown group calling themselves the Dark Harvest Commandos issued an ultimatum: clean up or face an Anthrax nightmare. This early attempt at bioterrorism serves as a reminder that such dangers still exist today.

The Island of Gruinard

Gruinard Island is nestled in Gruinard Bay on the west coast of Ross and Cromarty,  where it sits like a forgotten gem between Gairloch and Ullapool. This quaint, oval-shaped island spans just 484 acres, stretching 1.2 miles in length and 0.6 miles in width, and is only 0.7 miles from the mainland.

In 1881, six souls called this island home, but by the 1930s, human life had faded away, leaving behind the haunting remnants of cottages and field walls. Habitation was restricted to a few sheep grazing its fields, visiting hunters seeking game, fishermen, egg collectors, and picnickers. When left alone, the island's inhabitants were mostly rabbits and visiting birds, making it a tranquil, slightly mystical retreat.

Early Germ Warfare

In the 1930s, British Intelligence believed that the Axis powers were conducting germ warfare research and were worried about the threat of them using germ weapons.

Later, with Nazi forces advancing and knowing the horrors of World War I gas use, Winston Churchill saw the need for a British germ warfare weapon as a deterrent against Nazi first-use. The feasibility of biological weapons was investigated to ensure the British could threaten retaliation if necessary. This weapon would be called the N-Bomb.


Anthrax is a lethal bacterium, especially when inhaled, and it proves fatal in almost all cases, even with medical treatment. Just a small amount of anthrax, if weaponized, could devastate a major city, potentially killing millions.

The Germ Programme

In 1942, the War Office bought Gruinard Island, designated X-Base, for £500, banning all visitors. Under their direction, Porton Down experts conducted tests with small explosives loaded with anthrax spores, using sheep to determine the spores' effects. Initially, there was no effect on the animals, but they began collapsing and dying within three days, with blood oozing before death. However, the island was too small for larger tests and was abandoned.

By D-Day, the N-weapon was deemed less useful for battlefields, and the end of the war took away any urgency to acquire a tactical biological weapon. But the programme was still highly secret, and when dead sheep began washing ashore, the Secret Service concocted a cover story involving Greek sailors dumping infected carcasses.

Churchill's anthrax bomb was never used.

By the end of the war, Gruinard had been poisoned, burned, and abandoned. It remained off-limits, and it was not until 24 years after the experiment that the warning signs even mentioned anthrax.

The Dark Harvest Commandos

In 1981, a group calling itself the Dark Harvest Commandos issued threats, vowing to leave soil samples from Gruinard at strategic points to compel government decontamination action. Dubbed "Operation Dark Harvest," they demanded the decontamination of Gruinard, promising to educate the public. A package left outside Porton Down tested positive for anthrax, while another left at a Conservative Party conference in Blackpool contained soil resembling that of Gruinard, although this soil tested negative for anthrax.

The actions of this group represent an early and rare example of the threat of bioterrorism.

Attempts were made to find the culprits, and the Police believed it must be someone in the local community. Investigating officers were met with a wall of silence, and they firmly believed that more was known in the community than was being said.

With no suspects arising from the investigation, suspicion fell on a range of anti-nuclear activists, fervent Scottish nationalists, and people living alternative lifestyles. Despite this suspicion, no arrests were ever made. The Dark Harvest Commandos disappeared as quickly as they appeared, with the final, slightly ominous declaration that their work was done for now.


Whether as a result of the Dark Harvest Commandos or just making amends for wartime action, in 1986, a massive effort began to decontaminate Gruinard Island. Formaldehyde solution diluted in seawater was sprayed over the entire island, while heavily contaminated topsoil was removed. Sheep were reintroduced and remained healthy. By April 24, 1990, after 48 years of quarantine and 4 years post-decontamination, the MOD declared the island safe by removing the warning signs that ringed the island’s beaches.

In 1990, the island was repurchased by the original owner's heirs for the 1942 price of £500. While some controversy over the island’s past remains, it has largely lived in peaceful isolation.

Other Bio Sites

Britain was not the only country to conduct advanced weapons research using anthrax.

Vozrozhdeniya Island, or Rebirth Island, once an Aral Sea Island, expanded due to river damming for Soviet agricultural projects. This island served as a major facility for the Soviet Microbiological Warfare Group, housing a top-secret bioweapons facility from 1948, testing various agents like anthrax, smallpox, and plague.

Unlike the Gruinard decontamination effort, laboratory staff at this facility simply abandoned the small island in 1992, leaving behind containers of spores that were not properly stored or destroyed, resulting in leaks. In 2002, with assistance from Uzbekistan, the United States Department of Defense's Threat Reduction Agency organized the decontamination of 10 anthrax burial sites. A large team spent three months neutralizing an estimated 100 to 200 tonnes of anthrax at a cost of US$5,000,000. In doing so, they probably cleaned up the world's largest anthrax dumping grounds.

But do more exist? It’s quite likely.

The Moral of Guinard and Other Places

It’s really quite simple. We interfere with the natural elements that exist in our world at our peril. What seems like expedient wartime necessity at the time can create long-term problems that take long periods, resources, and risk to solve.

This serves as a reminder that while the Ministry of Defence may acknowledge and take responsibility for past actions, this level of accountability may not be present in other countries. The extent of previous biological warfare programs raises concerns about the potential existence of hidden threats in remote areas. Additionally, it highlights the proximity of the threat of bioterrorism that may be underestimated. While the actions of the Dark Harvest Commandos may evoke nostalgic reminiscence of the fictional insular community spirit found in Whisky Galore, their intentions were deadly serious.

In today's world, more resourceful and credible groups exist, underscoring the importance of remaining vigilant against all CBRN threats.

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Topics: Chemical warfare

Steven Pike

Written by Steven Pike

Steven Pike is the Founder and Managing Director of Argon Electronics (UK) Ltd. A graduate of the University of Hertfordshire, Steven has been awarded a number of international patents relating to the field of hazardous material training systems and technology.