Winter Survey Finds Gladstone Fish Healing20 August 2012
AUSTRALIA - Fish sampling conducted in June and July has found fish health in Gladstone waters is continuing to improve, even in the tougher conditions of winter.
Fisheries Queensland has released its latest survey report, which found fish to be in overall good health within Gladstone, including the harbour and spoil grounds.
Fisheries Queensland biologist Dr Stephen Wesche said the most significant finding was evidence of fish healing from previous injuries.
"We caught barramundi in the Boyne, Calliope and Burnett Rivers with recovering lesions - there was clearly new skin and scales growing over the lesions," Dr Wesche said.
"The advanced stage of healing on some of the fish indicates the injuries occurred prior to 2012.
"This evidence of healing is great news for local fish populations, as it points to the resilience of the fish and that their previous ill health is being overcome.
"It is particularly encouraging to see this healing continue during winter, which can be a tougher season for fish such as barramundi.
"Of the 93 barramundi observed, none had Neobenedenia parasites, eye problems or ulcerative lesions."
Dr Wesche said there were also no significant signs of ill health observed with other fish species, including grinner, Australian threadfin and Castelnau´s herring.
"Both within Gladstone and at the reference sites in the Fitzroy River and Bundaberg, the fish were in good condition," he said.
"We did observe some queenfish with parasites, but these parasites are naturally occurring in the environment and the number on the fish was not abnormal.
"We recorded observations from 273 banana prawns, and they were all considered to be in good condition except for three with shell erosion from Gladstone and the Fitzroy River, and three with a parasite on the gills from Bundaberg and the Fitzroy River.
"Mud crab sampling also continues to observe a very low prevalence of shell abnormalities, ranging from 1.4 per cent to 4.7 per cent of the 746 mud crabs caught across the study area. These figures are similar to past studies, which have reported a background prevalence of five per cent for shell disease in other crustacean populations.
"Tissue samples were collected during the June/July sampling for further processing.
"The final sampling trip will be in September, which will then give us a full 12 months of data to assess seasonal influences on fish health."
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