04/05/2005– Mediterranean
wild fish are exposed to exotic viruses because
of huge quantities of imported feed-fish used
in tuna farming, says a report launched today
by WWF. The global conservation organization
is therefore asking the EU to urgently ban
the use of non-Mediterranean fish as feed
in tuna farming.
The report shows that during their captivity,
which lasts about six months, tunas are fed
on large quantities of feed-fish. Most of
it consists of imported frozen, untreated
fish from other regions (West Africa, the
North Atlantic, and North and South America)
and involves non-Mediterranean species such
as herring or capelin.
As a result, as much as 225,000 tonnes of
feed-fish – most of them alien to the region
– are used annually by tuna farms in the Mediterranean,
a higher number than the area’s annual catch
of sardines. This could lead to the introduction
of new viruses that might affect the whole
Mediterranean ecosystem.
“Dumping of imported feed-fish into the Mediterranean
tuna farms must stop immediately. It threatens
both the health of local fish populations
and ecosystems and the livelihoods of fishermen
that rely on them,” said Dr Sergi Tudela,
Fisheries Coordinator with WWF's Mediterranean
Programme Office.
With Spain, Malta, Italy, Greece, and Cyprus
accounting for 71 per cent of the officially
declared tuna farming activity in the Mediterranean,
the problem is mainly European and the EU
has the responsibility to halt the threats.
The WWF report highlights the case of alien
feed-fish imports dumped by tuna farms in
Australia in the 11000s. Massive imports of
small fish from other regions were at the
origin of viral epidemics that in 1995 affected
5,000km of coastline and killed 75 per cent
of the adult sardine population in Australia.
“The risk of disease transmission is very
high. Most fish viruses rely either on direct
feeding or proximity to spread, and we set
up a classic transmission experiment every
time we feed sardines to tuna,” said Dr Brian
Jones, fish pathologist with Western Australia’s
Department of Fisheries and expert on the
Australian case.
“It is technically impossible to analyze
regularly frozen feed-fish imports to ensure
that they are free from harmful viruses. The
only solution is to have a total ban of such
practices. In Denmark, use of feed fish in
saltwater aquaculture has been banned since
1985. The EU should take the same approach
to Mediterranean tuna farms,” added Dr Tudela.
NOTE
• Drs Brian Jones and Daniel Gaughan, fish
pathologists with Western Australia’s Department
of Fisheries, contributed substantially to
WWF report.
