20. MINIMUM COMMUNITY MEASURES FOR
THE CONTROL OF CERTAIN FISH DISEASES (11025/99)
Letter from Lord Tordoff, Chairman of
the Committee, to Elliot Morley Esq MP, Parliamentary Secretary,
Ministry of Agriculture, Fisheries and Food
The Sub-Committee considered this Proposal at
its meeting on 20 October 1999 and agreed to maintain the scrutiny
reserve pending further information from the Government.
The Sub-Committee believes that Infectious Salmon
Anaemia (ISA) is a serious disease, and they would be grateful
for reassurance that the Government feels the same way. The Sub-Committee
is not yet convinced that relaxing the policy of compulsory slaughter
by allowing a delay will prove effective in combating the disease,
and they would like to know on what grounds the relaxing of the
policy has been justified, and whether ISA will remain a List
1 disease.
In addition, the Sub-Committee believes that
thorough investigations are required when outbreaks occur, and
they are not yet satisfied that last year's outbreak has been
fully explained. In relation to that outbreak, the Sub-Committee
would like to know whether the origin of the epizootic has been
determined by the Scottish Office investigation, and also what
risks to wild fish have been identified.
The Sub-Committee will reconsider the proposal
once they have received the necessary clarification.
25 October 1999
Letter from Elliot Morley, Minister for
Fisheries and the Countryside, Ministry of Agriculture, Fisheries
and Food, to Lord Tordoff, Chairman of the Committee
Thank you for your letter of 25 October asking
for further information on the above proposal concerning the control
arrangements for the serious fish disease Infectious Salmon Anaemia
(ISA).
In your letter you raised a number of queries
which are addressed in turn in the attached paper. I hope that
the information provided will allow Sub-Committee D to lift the
scrutiny reserve on this proposal which, as you know, the Government
fully supports.
18 November 1999
ADDITIONAL INFORMATION IN RESPONSE TO QUERIES
FROM THE HOUSE OF LORDS SUB-COMMITTEE D
SERIOUSNESS OF
INFECTIOUS SALMON
ANAEMIA (ISA)?
1. ISA is one of a number of serious fish diseases.
Clinical outbreaks can cause high mortalities in farmed Atlantic
salmon. There is no effective treatment or cure for ISA but a
vaccine is currently under trial in Canada and under development
in the UK. ISA was first identified in Norway in 1984 and in Canada
in 1996 and both countries are taking action to try and eradicate
the disease.
EFFECTIVENESS OF
THE COMMISSION
PROPOSAL IN
COMBATING THE
DISEASE?
2. The Commission proposal, inspired by the
UK, is consistent with Community legislation which requires action
to eradicate outbreaks of List I diseases. The introduction of
discretion in the timing of removal of fish from infected farms
will allow the official service to take into account the particular
circumstances on the affected site, including fish welfare considerations,
in determining the period over which the fish must be removed.
For example, a remote farm with low mortalities or few clinical
signs in the fish might be allowed a cage by cage clearance programme
based on mortality triggers. On the other hand, an infected farm
close to other uninfected farms and suffering high mortalities
would be required to clear as soon as possible.
3. Effective disease control will remain the
primary consideration in determining the timing of removal of
fish from an infected farm and the official service will retain
the option to order immediate withdrawal of fish if it is thought
to be necessary.
4. Norway has been operating an ISA control
programme along similar lines to that envisaged in the Commission
proposal and this has been successful in reducing the incidence
from over 100 cases in 1990 to just 13 in 1998.
JUSTIFICATION FOR
RELAXING THE
CONTROL POLICY?
5. The Commission proposal is not a relaxation
of the control policy. It will allow a more practical and targeted
control policy appropriate for the disease. The current requirement
for immediate withdrawal of fish from infected farms has been
found to be impractical where several thousand tonnes of fish
are on the site; in such cases a programme for their phased withdrawal
is necessary. In the Government's view, the changes proposed will,
along with the other key measures in particular restrictions on
movements of fish, people and equipment liable to transmit disease
and site fallowing requirements, reduce the economic impact of
the controls on the Scottish salmon farming industry without lowering
their effectiveness.
WILL ISA REMAIN
A LIST
1 DISEASE?
6. The Commission proposal does not affect
the List I status of ISA. List I status is not indicative of the
seriousness of the disease. It signifies a disease that is exotic
to the Community and which poses a serious threat to the aquaculture
sector. Clearly, if this perception were to change, the Commission
would wish to revisit the matter.
PROGRESS IN
DETERMINING THE
ORIGIN OF
THE OUTBREAK
OF ISA IN
SCOTLAND?
7. Work is ongoing in a number of different
areas including the sampling of wild fish to test for the presence
of the ISA virus, comparison of the Scottish ISA virus strain
with that found in Norway and Canada and investigations of the
circumstances of the outbreaks in Scotland to determine how infection
might have been spread. As yet there is insufficient evidence
to come to a definitive conclusion but the balance of evidence
suggests that the Scottish outbreak has a point source and infection
is likely to have been spread by movement of people and equipment.
What led to the first outbreak remains unclear but the possibility
of wild fish infecting farmed fish cannot be ruled out. Work on
the origin of the ISA outbreaks in farmed Atlantic salmon is being
carried out in Norway and Canada but there too no conclusions
have yet been reached.
WHAT IS
KNOWN OF
THE RISKS
TO WILD
FISH?
8. Investigations carried out by scientists
in Canada and in Scotland have found evidence of the presence
of the ISA virus in wild fish. The presence of the virus has been
detected in wild fish sampled during recent surveillance. These
include:
— Sea trout in Laxo Voe, Shetland;
and the River Snizort in Skye; and
— Eel in Loch Uisg, Mull.
Other laboratory results indicate that the virus
may also be present in other wild fish and farmed fish in freshwater.
These include:
— Brown trout in the Rivers Conan and
Easaidh;
— Atlantic salmon parr in the Rivers
Conan, Easaidh and the Tweed; and
— Rainbow trout in freshwater farms
in Aberdeenshire and Kinrosshire.
There is, however, as yet no evidence of the
disease itself in wild fish and it is not known what effect the
presence of the virus has on wild fish populations. Nor is it
known whether the virus has spread from fish farms or is naturally
present at low levels in wild fish, although the geographic spread
of the sites where the virus has been detected or is suspected
suggests the latter.
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