The only factor that was different in 2011 compared to previous and following years was the significant rainfall, the subsequent flooding and introduction of large numbers of fish from Lake Awoonga, which stressed the ecosystem.
This stress led to fish being more susceptible to ill health, particularly parasites that contributed to the conditions observed in fish.
Test results confirmed the parasitic flatworm (skin fluke) on some barramundi caught in the Gladstone area. Find out more about the parasitic flatworm.
A different parasitic flatworm was identified on sharks. Shell erosion was detected on crabs and prawns, which is due to relatively common bacteria.
Fish health in Gladstone has now returned to a more normal situation, with market reports finding most fish in good condition and a low incidence of shell erosion on mud crabs.