A British zoologist was denied an entomology job because she was a woman; in 1945, at just 24, she went alone to a landlocked African nation and helped transform the study of tropical tilapia, one of the world’s most consumed fish

After the Second World War, a British scientist by the name of Rosemary Helen Lowe wanted to work as an entomologist. But in 1945, the Colonial Service refused to employ female entomologists. Instead of giving up on her ambition to become a field scientist, Lowe-McConnell, whose father was Liverpool’s deputy director of education at the time, turned to ichthyology, the study of fish.

That decision eventually took her to Malawi (formerly Nyasaland), a relatively small landlocked southeastern African nation, endowed with spectacular highlands and extensive lakes. She helped establish a laboratory and studied the freshwater fish of Lake Nyasa, now Lake Malawi. Her work on cichlids, particularly tilapia, became an important foundation for later studies of tropical fisheries and fish farming.

A childhood dream took her to Africa

Born in Liverpool in 1921, Lowe-McConnell developed a fascination with nature early in life. She grew up close to the River Mersey, where she watched wading birds, while her family kept animals ranging from stick insects to a donkey. Her father also had an aquarium of tropical fish.

Lowe-McConnell's childhood ambition was to become an explorer in Africa. One of her teachers, however, responded to that dream with the suggestion that “perhaps you can teach,” according to The Guardian, recounting her life.

She went on to study zoology and botany at Liverpool University before joining the Freshwater Biological Association at Lake Windermere. Her early work involved projects on producing food from freshwater during wartime.

The misogynist rejection that changed her scientific path

In 1945, the Colonial Service rejected Ro for being a female entomologist, prompting her to pursue ichthyology. In the same year was sent to Malawi to continue a fishery survey that had begun in 1938. The assignment was anything but an ordinary research trip. Before leaving, she had to learn how to use and repair field equipment, identify fish species and learn the basics of the local language.

She traveled alone by ship to South Africa, then by train to Southern Rhodesia (now Zimbabwe), before continuing by road to Nyasaland, now Malawi, according to the International Society of Limnology. She also carried 14 crates of heavy field equipment on the journey, The Guardian reported.

At Lake Nyasa, the cichlid fish she studied were an important source of protein for local communities. Lowe-McConnell's work, therefore, had both scientific and practical importance: understanding the fish was also part of understanding how to develop a sustainable fishery.

The tilapia research from Africa

Lowe-McConnell returned to Africa in 1948 after a brief period in her home country to write up her Malawi report, now working from Jinja, Uganda, at the East African Fisheries Research Organization.

Her main focus was the biology of tilapia in the lakes of East Africa. She produced a large body of scientific research that later helped researchers examine the effects of fishing and other human activities on fish populations. Her studies on the important food source for many communities in both the developing and developed worlds also provided a valuable foundation for further research on fish farming in tropical waters.

Blue Life Hub, in its overview of the global tilapia trade, estimates that more than 7 million tonnes of tilapia were produced worldwide in 2024, with the USA remaining the world's largest tilapia consumer. Asia accounted for more than 67% of that production, with China remaining the leading producer and Indonesia growing rapidly.

The fish Lowe-McConnell studied in African lakes is now part of a huge global aquaculture industry, which is affordable for most parts of the world.

Her fieldwork was full of unexpected moments

Lowe-McConnell's scientific life was also an adventurous one. Her autobiography ‘The Tilapia Trail’ accounts for some of the adventures during her exploration during one expedition, when the reverse gear of her car failed, and local people simply picked up the vehicle and turned it around.

She also had to chase hippos away from her garden on the shores of Lake Victoria so they would eat her neighbors' cabbages rather than her own.

And when construction of the Owen Falls dam temporarily exposed the bed of the Nile, Lowe-McConnell and her colleagues rushed down to explore it. Their expedition resulted in the discovery of a new species of fish, although the available account does not name it.

Her later fieldwork took her to Botswana and British Guiana, where she continued studying freshwater fish and fisheries.

Woman in science working against the rules of time

The obstacles Lowe-McConnell faced did not end with the Colonial Service decision. In 1953, she married geologist Richard McConnell. Because of the “marriage bar” for women in place at the time, she was required to resign from her position. The Linnean Society notes that a female friend was later ironically hired as an entomologist after officials reviewed Lowe-McConnell's experience and concluded that nothing “untoward had happened as a result of appointing a female.”

Despite those restrictions, Lowe-McConnell continued working across decades. She later participated in international conferences on ichthyology, limnology and ecology and produced publications bringing together research on freshwater fish in tropical Africa, South America and Asia. Her 1987 book Ecological Studies in Tropical Fish Communities became a major work in the field.

She also documented her experiences in Land of Waters and The Tilapia Trail, the latter published in 2006.

The scientist eventually received three major medals

Due recognition was given by several scientific organizations. Lowe-McConnell received the Naumann-Thienemann Medal in 1995 from the International Society of Limnology. In 1997, she was awarded the Linnean Medal for Zoology for her studies of freshwater fish in Africa and South America. In 2000, the Fisheries Society of the British Isles presented her with the Beverton Medal for her contribution to fish biology and fisheries science.

Rosemary Lowe-McConnell died in 2014 at the age of 93. By then, the woman who had once been prevented from pursuing entomology had already studied freshwater ecosystems across Africa, South America and Asia. And the research helped provide a foundation for later studies of tropical fisheries, particularly the biology and management of tilapia.