Latest results from fish sampling in Gladstone in December have shown encouraging signs of improvement in fish health.
Fisheries Queensland Habitat and Assessment General Manager John Robertson said observers went out fishing in December with commercial fishers to monitor fish health in the harbour and surrounding waters.
"We caught and visually inspected 37 barramundi from the harbour and 517 from the freshwater section of the Boyne River," Dr Robertson said.
"It's still early days, but we've found a general improvement in the health of barramundi from the harbour in December 2011 compared to our monitoring in October 2011 with the percentage of totally healthy barramundi increasing from 32% to 54%.
"There was a noticeable decrease in the number of barramundi with eye problems and lesions, and although skin redness was still present, it was not to the extent we had seen previously.
"Only one fish (3%) was observed with an eye problem in December compared with 39% in October, while the percentage of barramundi with lesions or ulcerations decreased from 17% to 8%.
"There were also no external parasites on barramundi observed in December."
Dr Robertson said barramundi were surveyed in the freshwater section of the Boyne River to tag fish to monitor their movement and any change in health condition over time.
"All barramundi caught in the freshwater were in a healthy condition," Dr Robertson said.
"Other fin fish species also continue to be monitored in the harbour, with 95% of the 197 fish examined in December found to be healthy, which is consistent with October findings.
"Of the 29 sharks and rays caught in Gladstone, none had lesions and 13 sharks had minor discolouration. Only one shark was described as having a large area of skin discolouration and one with discolouration over the majority of its body."
Dr Robertson said mud crabs were sampled extensively in December after reports from commercial fishers about shell abnormalities.
"Fisheries Queensland observers went out with a number of commercial mud crab fishers to monitor the fishery from the Narrows south to Turkey Beach," Dr Robertson said.
"Of the 939 mud crabs observed, only 6% were identified as having shell abnormalities, which is similar to levels previously documented in the late 1990s.
"We have a lot more sampling and testing we want to do before we can have a final assessment of fish and crustacean health, but at least these results are a positive sign for Gladstone fishers.
"To help us build the full picture of fish health, we urge commercial fishers to report catches of ill health, including the proportion of the whole catch and the location."
To report fish showing signs of ill health, contact Fisheries Queensland on 13 25 23.
For a copy of the latest fish sampling report, visit www.qld.gov.au/gladstoneharbour