By John Mosig
By John Mosig
The last issue of Hatchery International brought readers partially up to date with recent developments in the Sunland fish hatchery saga.
To recap: Gwen Gilson, at her Sunland Fish Hatchery, located near Lake Cootharaba on Queensland’s Sunshine Coast, had successfully raised Australian bass (Macquaria novemaculeata) for many years until the early 1990s when spraying commenced at a newly planted macadamia grove. The hatchery suffered occasional kills and larval deformities, which intensified in 2005, at the same time as the macadamia farm upgraded its spray rig to put a larger plume of chemicals into the atmosphere.
Complaints to Queensland State Authorities resulted in the establishment of the Noosa Fish Health Investigation Taskforce in January 2009. Its role was to investigate fish health problems at the Sunland Fish Hatchery, and broader fish health issues associated with the Noosa River catchment.
The report was completed in 2010, but not released until 2011 owing to ongoing court proceedings – Gwen had also filed a legal suit against the neighbouring macadamia farm calling for damages, and a cease and desist order.
The Department of Agriculture Fisheries & Forestry’s Chief Biosecurity Officer and Taskforce Chair, Dr. Jim Thompson, responding to a request for information wrote that the Task Force’s final report had 29 recommendations directed to the macadamia and aquaculture industries, the APVMA, and to state and local governments. One of the recommendations addressed the need to determine the potential effects of agricultural spraying in the local catchment area, specifically on bass in the Noosa River System.
Thompson noted that a program of tagging and monitoring bass in the Noosa River by Infofish Services, a private organization that works with anglers around the state, had continued. On average, 30–50 Australian bass have been tagged each year, and, according to Infofish’s manager Bill Sawynok the organization is collecting fishing data. A number of people go to the Noosa Lakes once a year, and generally tag all the bass that they catch, but very few that actually fish there keep any statistics, and apparently no one working with Infofish has a good sense of what’s happening in the river.
The last comprehensive Infofish report was in 2009 and included the following statement:
The size/frequency data [had] indicated a normal distribution of fish with an average size tagged [ranging] from 250-299mm. There was a steady increase in the average size of fish tagged from the mid 1980s to the mid 1990s, however little change beyond that time. It is possible that there was increased recruitment during the 1980s, which is reflected in the increase in the average fish length from the mid 1980s to the mid 1990s. From the mid 1990s to the present there is little evidence of any substantial boost in recruitment at any time.
Infofish Services said they were looking to do an update on Noosa Bass at some stage in the near future.
Commercial fishermen witness declines
But there have been other observers besides the recreational anglers: Errol Lindsay has spent 46 years commercial fishing this area and has seen dramatic changes over the last few years.
“The bass we catch as a returned by-catch are increasing in size and there’s just no little fellas,” he said. “That indicates to me that there’s no recruitment of young bass in the system.” Other species are also very scarce. “Fifteen or twenty years ago these lakes were full of freshwater mullet [Myxus petardi], fork-tailed catfish [Arius graffei] and bony bream [Nematalosa erebi]. They have all gone. The fish we’re picking up are getting larger each year and we’re not finding any young stock. The bony bream are prolific breeders and an important source of crayfish bait. We used to have no trouble getting hauls of 400-500kg of small bream of less than 200mm. Now 300kg is a very, very good shot, and the sizes are getting up towards 400mm.
“The catfish are mouth breeders, and last spawning season we found any number of globules of eggs … just lying on the bottom, as big as a man’s fist. Something’s not right. The crustaceans are suffering too. We haven’t seen a decent prawn season for about 15 years. These things really do concern me.” Errol concluded.
Sampling from environmental recording stations throughout the Noosa system has found traces of a wide range of domestic and agricultural chemicals, but all have been below what the regulations proscribe as ‘threshold’ levels. Among the most ubiquitous was Carbendazim, which has been shown to damage the development of the testicles and production of sperm in rats and the growth of mammals in utero. The German Federal Government lists it as a potential human hormone-disrupting chemical.
Nonetheless, in an appendix to the Sunland Taskforce Report, Dr Munro R. Mortimer, the Senior Principal Scientist of the Department of Environment and Resource Management stated that:
“For chemicals which were detected, and for which there is a guideline trigger value, there appears to be negligible risk of harm to fish health in the Noosa River system over the extent covered by the EPA/DERM sampling in 2009-2010, because the concentrations detected are less than the trigger values.”
However, the two reports – Infofish Services’ data collection, and the observations of a professional fisherman – suggest that there has been interference with the spawning cycle of the species that breed in the Noosa Lakes.
Sadly, circumstances that warrant rigorous scientific investigation and thorough bureaucratic administration appear to have been given a glossy coat of paint, and put back on the shelf.
— John Mosig