How would you go trying this nowadays?
"Fishery gets first buoyancy test
In 1969, banana prawn catches dropped to half that of the previous year, raising concerns the fishery had grown too fast. A CSIRO project was begun to establish what quantities of prawns could be caught without overfishing, and predict catches by assessing juvenile prawn numbers in nursery areas. Small boats were used to sample estuaries in Western Australia. In the Gulf of Carpentaria, float-planes were used. The planes flew from estuary to estuary, landing on the water and then towing a beam trawl to catch small prawns.
Collecting prawn samples from a float-plane in a remote gulf river. "
CSIRO