Toxicology results on sick fish
FISHERIES Queensland has released toxicology results which find no evidence that metals or organic chemicals are causing fish disease in Gladstone Harbour.
Fisheries released the report today saying it provided results of "preliminary toxicology testing."
The report only covers results from three barramundi taken from Port Alma and China Bay in September.
Fisheries Queensland Habitat and Assessment General Manager John Robertson said testing on other samples was continuing.
"There is no indication from these preliminary results that organic chemicals or metals are affecting the health of fish in Gladstone Harbour, but further testing will be required due to the small sample size," Dr Robertson said.
A copy of the report can be found at www.qld.gov.au/gladstoneharbour.
"These results are the first of the toxicology tests, which can take up to eight weeks, and more samples on a range of fish species are currently undergoing testing.
"Testing for organic chemicals and metals was conducted on the liver, gill and muscles of each fish, which were some of the first fish with lesions submitted for testing.
"The samples submitted were tested for more than 160 organic chemicals such as pesticides, agricultural chemicals, herbicides, petrochemicals and contaminants. In addition, samples were tested for eleven metals.
"Ten metals were detected across the range of samples and it is not unexpected that relatively higher levels of aluminium, iron and zinc were found in a number of samples.
"Based on an initial analysis of scientific literature from Australia and overseas the levels of metals detected are not considered a problem for fish health.
"Of the samples tested, only one organic chemical was detected in one sample.
"The only organic chemical found at a detectable level was an environmental breakdown product of DDT, which was found in the muscle tissue of one fish from China Bay.
"DDT was a pesticide that was commonly used in the agricultural sector, but has not been permitted in Australia for more than 20 years.
"Because of its previous wide use, it's taking a while for the chemical to completely leave the environment and it is not uncommon for low levels to be found in Queensland waters.
"While these initial toxicology results seem to indicate organic chemicals and metals did not impact the health of these fish, we are continuing to do more testing, including tests on healthy fish, to get a broader understanding of the issue."
Dr Robertson said that in addition to the toxicology results, new test results on fish and crustacean samples from Gladstone had also been released.
The release of the toxicology results comes a day after commercial mud-crabbers presented a box ful of live crabs to the media, with what appeared to be some form of ulcer on their shells.
Responding to the crabbers' concerns, Independent Member for Gladstone Liz Cunningham said more needed to be done to determine the factors leading to various problems in Gladstone Harbour this year.
"All this does is add weight to the calls for a concerted effort to find what's been causing problems in the harbour," she said. "It reinforced the fishing industry's concerns and the need to find answers."
She also said the Oversight Committee set up to engage various stakeholders and strengthen the search for answers was not getting any closer to finding answers, and it's weekly teleconference meetings, in which she has participated, were "as useful as an ashtray on a motorbike."
DDT not to blame
Speaking after the release of Fisheries' toxicology reports Director-General of the Department of Environment and Resource Management Jim Reeves said it was highly unlikely DDT or metals at the low levels reported would cause fish illness of the type seen in Gladstone.
"Observations of the data by Safe Food Production Queensland and Queensland Health indicate none of the samples appear to have exceeded the residue limits set by the Food Standards Code for fish," Mr Reeves said.
"I would stress that this is only the beginning of such testing, we are not drawing any broad conclusions from these results for Gladstone fish, as more toxicology testing is continuing on other fish, molluscs and crustaceans.
"The parasite that was found on some shark samples was identified as a parasitic flatworm, which has been found on sharks in other areas of Queensland, including recently in the Kolan and Fitzroy rivers.
"This flatworm is a different parasite to the one found on the barramundi, which was a Neobenedenia species.
"As per previous test results, no bacterial, parasitic or fungal pathogen could be identified as the cause of the skin discolouration on the whiting, trevally, spangled emperor or spotted cod samples.
"Shell erosion was also identified on some crabs and prawns, caused by bacteria, which again are commonly found in marine waters affecting crustaceans.
"Tapeworm parasites were identified on prawn samples, which are not unexpected in wild prawn populations and would not have significantly affected prawn health.
"Testing of more barramundi samples was also consistent with previous results, identifying the parasitic flatworm as the major contributor of eye and skin damage.
"All of these latest test results have been submitted to the independent scientific panel for review.
"We are continuing to work with commercial fishers to conduct monitoring and collect more samples for testing.
"Overall, we are starting to build a better picture of the status of fish health in Gladstone, backed by strong scientific evidence."