The Department of Health Environmental Health Service
(EHS) has conducted an
investigation into reports of illness associated with the sale of a
fish described as "rudderfish" in South Australia.
It has been determined that the fish has the
scientific name of Lepidocybium flavobrunneum. It is described
in the Australian Seafood Handbook as "escolar".
A joint industry government committee has
established the approved marketing names for fish listed in the
Handbook. Use of standardised names is largely voluntary and depends
on support from the industry.
The EHS has received reports of 98 cases
of illness attributed to the consumption of "rudderfish"
(escolar). Most of these reports followed recent media attention to
the issue. The illnesses ranged from mild diarrhoea to severe
diarrhoea with nausea and vomiting. It is thought that the cause of
the problem is the quantity and composition of the oil in the fish.
Oil from "rudderfish" (escolar) is
mostly waxy esters (94-98%). These are a chemically different class of
oil to that found in most food oils from fish, animal or plant
sources. They are thought to be largely indigestible.
Industry estimates that 40-50 tonne of
"rudderfish" (escolar) is sold annually in South Australia,
which equates to approximately 140 thousand fillets. Most originates
in Queensland or Western Australia. Commercial catches are not made in
South Australia.
A majority of people who consume
"rudderfish" (escolar) do not report untoward symptoms.
There may be seasonal or other variables that affect the properties of
the fish. It is consumed in some other States of Australia and
internationally and its purgative property is well established.
Industry in South Australia has agreed to advise
customers of the properties of the fish by signage and direct advice
at the point of sale.
It is thought that consuming smaller quantities
may reduce the risk of illness but consumers who are concerned about
the risk, particularly those who are elderly or have a bowel
condition, should avoid this fish.
