Charged with harvesting vast amounts of seaweed – it could take 30 hours to collect enough for a single pound of agar – with limited funding, Marshall and Orr’s task was a challenging one.
A fascinating archive of letters between Marshall, Orr and the Ministry of Health suggest some the practicalities involved.
‘I think we could safely say that a small sum would be paid to local boy scouts and school children who participated’, the Ministry wrote to Orr in 1942.
Enlisting local children to collect seaweed in exchange for pocket money had proved highly successful in New Zealand, as botanist Lucy Moore – working on the same problem in Wellington – had already found. The grounds of Millport were pressed into service for drying out the huge piles of weed, which could then be processed into agar.
Postwar Scottish agar production did not continue for long – seaweeds from other countries ultimately proving better sources – and Marshall returned to her work on copepods.
In 1949, she became one of the first five women invited to join the Royal Society of Edinburgh, and became Deputy Director of Millport in 1962. Retiring in 1964, she continued to work informally at the station, spending her 70s travelling to marine laboratories around the world.