Solving the mystery of mass bird deaths
Several years ago the town of Esperance woke – after three days of 40 degree plus days- to find hundreds of dead birds. There was concern that whatever had killed the birds could also affect people. ChemCentre tested the birds for a range of potentially toxic materials. Other scientists from the then Department of Agriculture and PathWest tested the birds for disease and pathogens. The cause of the bird deaths was exposure to unusually high levels of lead. The lead compromised the birds’ resilience to the stresses of the sudden hot days an estimated 4,000 birds died. Further environmental testing was undertaken including samples from rainwater tanks, soil, sludge from gutters and within households to determine how widespread the lead contamination was.
ChemCentre developed techniques of low level isotopic ‘fingerprinting’ to determine the source of lead contamination. This technique was instrumental to the characterisation and assessment of the lead contamination. The source of lead and was traced to a mining company that was using bulk handling equipment to load dusty lead ore concentrate onto ships in Esperance port. The result was a cleanup of Esperance and surrounds, possibly the largest environmental cleanup (in terms of area) undertaken in Australia, as the investigation included the townsite and the transport corridor back to Menzies, almost 600km to the north east.
The project to return Esperance to a safe level, involved scientists from the Department of Health, ChemCentre, the then Departments of Water and Environment, the local shire, port and resident representatives. The errant mining company was fined almost $1M, the biggest penalty of its kind in WA at that time.