 |
Ref:570/03 |
|
|
 |
Australia
- Mar 4, 2003 |
|
|
Scientists to determine age of gulf kingfish
|
|
What does a fish have
in common with a tree?
They both have growth rings, which can be used to tell
how old they are.
In the case of kingfish, a study is being undertaken
of wild fish which will see their ear bones analysed.
As with trees, the individual growth layers will allow
scientists to determine the age of the fish.
South Australian Aquaculture Council chairman Bruce
Zippel, of Ceduna, said scientists will use this to
determine whether kingfish in the Spencer Gulf have
spent all their time in the wild or escaped from fish
farms.
It is expected that the growth rings on farmed fish
will be wider than those on wild fish, due to their
regular feeding.
Also, the age of fish in the wild will be able to be
determined, and this will show if they are older than
the first farmed in Spencer Gulf or otherwise.
"They are hoping to have some early results within
four months," Mr Zippel said.
"It is going to be independently undertaken by SARDI
and the University of Adelaide."
Mr Zippel said the study had come about following
opponents of fish farms launching a petition asking
the State Government to declare a moratorium on any
new fish farm development.
West Coast Professional Fisherman's Association
president Allan Suter, also of Ceduna, has estimated
that more than 1000 people will sign the petition.
"We have a network of commercial and recreational
fishers collaborating on this issue," Mr Suter said.
The petition states: "Escaped yellowtail kingfish are
damaging our fishing for whiting, squid, garfish,
Tommy ruffs and other species through predation and
colonisation of wild fish habitat.
"We are concerned that because of these escaped farm
fish, our wild fish fisheries and tourism are
suffering.
"Overseas experience has demonstrated serious damage
to the long term sustainability of all fish stocks and
their ecosystems."
Mr Zippel has cautioned people against signing the
petition without concrete evidence to link kingfish
sightings to the aquaculture industry.
"A moratorium on any section of the aquaculture
industry would be disastrous for this State," Mr
Zippel said.
"People have to appreciate that the announced research
will be comprehensive and fully independent.
"One of the main intents of the research program will
be to identify whether there is different behaviour
between wild and hatchery fish, to see if there is any
basis for the allegations."
He urged anyone with evidence that proved kingfish
seen in Spencer Gulf were hatchery fish to provide
that to Primary Industries and Resources SA (PIRSA). |
|
|
