Chef Julia Child Was A Shark-Fighting Secret Agent During World War II

Yes, that Julia Child.


Dr. Katie Spalding


Dr. Katie Spalding

Freelance Writer

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory.

Freelance Writer

Julia child was indeed once a spy for the US who invented shark repellents

“I must say we had lots of fun.” Image credit: ©Lynn Gilbert CC BY-SA 4.0, Taromon/, edited by IFLScience 

In many ways, cooking is just chemistry. You combine acids, bases, proteins, and various other chemicals, and subject them to a myriad of different physical and chemical processes like freezing, heating, mixing, and blending – it’s all classic lab stuff, but with cake at the end rather than, say, five kilos of primo coke.

This is why it shouldn’t be that surprising that Julia Child, the iconic American cook and TV personality, once worked for American intelligence on a wartime project to design and create an effective shark repellent.


But it definitely is, right?

Julia Child, war spy

Julia McWilliams, as she was known at the time, was just a 29-year-old copywriter in New York when the US joined World War II. By her own admission, she wasn’t even particularly interested in cooking at the time – having grown up with a family chef, the skill was simply something she had never learned.

In fact, she wanted to be a novelist. However, with the bombing of Pearl Harbor in December 1941, her plans changed. She decided to join up with the Women Accepted for Volunteer Emergency Service (WAVES) – a branch of the Navy and Women’s Army Auxiliary Corps (WAAC) in the Army.

There was just one problem: at 6 foot 2 (1.88 meters) tall, she was deemed too tall to be accepted. Instead, she applied to the newly-created Office of Strategic Services (OSS) – the organization which would eventually become the Central Intelligence Agency (CIA).


“Good impression, pleasant, alert, capable, very tall,” read the notes from her interview for the job, only declassified in 2008. And with that, Ms McWilliams was hired as a junior research assistant for the OSS – a position which, despite the job title, mostly involved typing the names and addresses of government officials on index cards.

It must have been incredibly boring, and declassified OSS files reveal McWilliams’s recollection of having “typed over 10,000 little white cards and put in for a transfer.” Luckily, her education and experience soon got her a new (and much more exciting) position within the agency: working under Captain Harold J. Coolidge in the Special Projects Division of the Emergency Sea Rescue Equipment (ERE) Section of the OSS. 

In a time beset by Nazis, biological warfare, and the creeping threat of nuclear weapons, there was one issue the agency saw as particularly troubling: the rampant threat of shark attacks.

The original sharkmania

We usually think of Jaws as responsible for the world’s collective irrationality over shark attacks – events which, it goes without saying, are incredibly rare and far outnumbered by human attacks on sharks


However, there was another, earlier, sharkmania that swept the US. “World War II played a pivotal role in fomenting the nation’s obsession with sharks,” University of Texas at Austin Distinguished Teaching Professor of American Studies Janet M. Davis explained in an article for The Conversation back in 2021. “The monumental wartime mobilization of millions of people placed more Americans into contact with sharks than at any prior time in history, spreading seeds of intrigue and fear toward the marine predators.”

Like any good national mass hysteria, the media soon locked into the trend, with local newspapers across the US running frequent stories about bombed ships and aircraft stuck at the mercy of the supposedly fearsome beasts. “Journalists consistently described imperiled servicemen who were rescued or dying in ‘shark-infested waters,’ Davis noted. “Whether sharks were visibly present or not, these news articles magnified a growing cultural anxiety of ubiquitous monsters lurking and poised to kill.”

The fear was so intense that it even influenced US military tactics. For most of the war, for example, the Lockheed P-38 was the primary long-range fighter aircraft of United States Army Air Forces in the southwest Pacific theater, due in at least some part to its perceived lower risk of shark attacks: General George Kenney, commander of the Allied Air Forces in the area, supported aircraft's use specifically because its twin engines and long range diminished the risk of going down over open water. 

“You look down from the cockpit and you can see schools of sharks swimming around,” he reportedly said. “They never look healthy to a man flying over them.”


Before long, the national preoccupation with sharks and shark attacks had become such a problem that U.S. Army and Navy intelligence operations had to launch publicity campaigns to combat the mass galeophobia. “Shark yarns inevitably become tall stories,” advised the 1942 Castaway’s Baedeker to the South Seas, a guide for servicemen in the Pacific theater published by the US Navy.

“Of the sixteen species of shark, only one, the tiger shark, is a serious threat to a man swimming in the water and your chances of meeting one of them are not great,” it reassured readers. “In general the shark is […] reluctant to attack any prey other than his usual diet of small fish – and there are plenty of fish to keep him well fed.”

An unfounded fear?

Despite this furor, shark attacks were hardly a common occurrence, with only 20 recorded across three years of wartime. So why was the OSS – and their young recruit Julia McWilliams – so invested in finding a working shark repellent? 

In part, the project was just a continuation of the Navy’s public outreach to provide some peace of mind to servicemen worried about being eaten by a marine monster. However, there was a genuine military need behind the research, too: the OSS was concerned by reports that sharks, blissfully unaware of human conflicts, had been accidentally setting off naval explosives meant for enemy ships and U-boats.


Researchers tested over 100 different substances over the year the project was running, with efforts focusing on trying to replicate the odor of a dead shark. Attempts ranged from the obvious, like decayed shark meat, to the artificial and chemically complex – but in the end, the team settled on a mixture consisting mainly of copper acetate and black dye. The idea was twofold: the copper acetate, it was thought, would repel the shark, while the dye would obscure any struggling seamen from the potentially hungry predators.

“The special nigrosine dye component produced a black cloud visible to the user and was said to mimic the natural defensive secretions of marine mollusks such as the squid and octopus,” explains a 2001 paper, published in the journal Environmental Biology of Fishes, on the history of shark repellents.

“The copper acetate component served two additional functions. First, it was recognized that copper ions inhibited the feeding of teleost fishes, and secondly, ammonium acetate, a major constituent in decomposing shark flesh, was also shown to be a feeding deterrent in the dogfish,” the paper continues. “It was therefore concluded that the combination of copper and acetate ions would produce an increased deterrent effect.”

In fact, the “Shark Chaser”, as the concoction was dubbed, was not all that effective – the success rate was only a little over 60 percent, and it failed to save those killed by sharks after the nightmare that was the sinking of the USS Indianapolis


However, the invention nevertheless had an important positive effect on the spirits of servicemen scared of going down in the Pacific, Samuel Gruber, then a biologist at the University of Miami, told ABC News in 2004. “You're flying around World War II and some kind of airplane shoots you down and you have something on your chest,” he explained. “It says ‘shark chaser.’ Whether it works or not, it did a tremendous amount for the morale of the pilots.”

Success or not, her work on the Shark Chaser project evidently left its mark on the young Julia – she would later refer to the repellent as the “first recipe” in her cooking career. 

“We designed rescue kits and other agent paraphernalia,” Child told fellow OSS Officer Betty McIntosh during an interview for the book Sisterhood of Spies.

“I must say we had lots of fun.”


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