Head Office Press Office
- 11-Jul-2007 - The Environment Agency fish
farms at Calverton and Leyland have lifted
their self-imposed ban on using only Tench
Rhabdovirus-free broodstock, following a
two-year investigation into the disease
and its distribution in rivers across England
and Wales.
The investigation was prompted by an outbreak
of the disease in 2004 at the two fish farms,
and the subsequent decision to clear and
disinfect both farms as a precautionary
measure.
"The 2004 decision was not an easy
one because we knew very little about the
distribution and the threat of the disease.
The virus had only been seen once before
in the UK and had been connected with a
number of fish deaths," explained Environment
Agency Fisheries Policy Advisor Paul Lidgett.
"We could not allow potentially infected
fish to be stocked into the wild and put
fisheries at risk. Since then we have only
used broodstock that has tested negative
for TeRV antibodies. This has meant that
we have become dependent on just a few sources
of broodstock, thus putting the long-term
production of certain species, especially
chub, dace and barbel, at risk.
"Since 2004 we have been using a new
technique developed by the Centre for Environment,
Fisheries and Aquaculture Science that identifies
which fish have been in contact with the
disease. This has helped us collect more
information on the distribution of TeRV.
We have used this information to review
whether the disease poses a continued threat
to our coarse fish farms and wild stocks
of coarse fish."
This review has concluded that TeRV is
widespread in most rivers throughout England
and Wales including the Thames, Severn,
Trent and Great Ouse, and that there is
no evidence of an impact on these populations
of wild fish.
The evidence was presented to the Environment
Agency’s Category 2 parasite review group,
an expert panel of fish health scientists,
in June. The panel consisted of, Nigel Hewlett,
and Chris Williams from the Environment
Agency, Professor Jimmy Turnbull from Stirling
University, Dr Ruth Kirk from Kingston University,
Bernice Brewster, a private fish health
consultant, and Dr Steve Feist from the
Centre for Environment, Fisheries and Aquaculture
Science.
"The review group agreed with our
findings and recommended the Environment
Agency lift its ban. The decision means
there are now no restrictions on broodstock
selection and our restocking programmes
will continue unabated," continued
Paul Lidgett.
Alan Henshaw, from the Evironment Agency’s
Calverton Fish Farm said: "This does
not mean we do not consider TeRV a threat
to our fish farms. Any disease on a fish
farm can cause problems. However, both Calverton
and Leyland now have the latest biosecurity
measures in place and this will reduce the
risk from TeRV and other diseases."
Fish suppliers and anglers to benefit from
Environment Agency decision to remove parasites
from banned list
Head Office Press Office - 11-Jul-2007
- The fish supply industry in England and
Wales is set to benefit to the tune of £500,000,
following the Environment Agency’s decision
to remove two parasites from its list of
controlled Category 2 pathogens.
Category 2 parasites include those that
are not native, but which have become established,
and which the Environment Agency considers
are a potential threat to native fish stocks.
"Environment Agency fisheries scientists
have been reviewing the list over the past
two years to see if the potential risks
continue to be borne out by the evidence.
They do not. The evidence has now been peer-reviewed
by a panel of Environment Agency scientists
and independent fish health experts,"
explained Environment Agency Fisheries Policy
Advisor Paul Lidgett.
The panel consisted of Nigel Hewlett, and
Chris Williams from the Environment Agency,
Prof. Jimmy Turnbull from Stirling University,
Dr Ruth Kirk from Kingston University, Bernice
Brewster, a private fish health consultant,
and Dr Steve Feist from the Centre for Environment,
Fisheries and Aquaculture Science.
The panel concluded that neither of the
two parasites - Atractolytocestus huronensis
and Paraergasilus longidigitus - pose a
significant threat to fish stocks, either
at an individual host or population level.
Atractolytocestus huronensis and Paraergasilus
longidigitus are parasites that appeared
in fisheries in the early 11000s. A. huronensis
is a tapeworm that lives in the gut of common
carp and its variants. P. longidigitus is
a crustacean that infects the nasal cavity
of a wide variety of coarse and salmonid
species.
"I think this is the right decision,"
confirmed fish health consultant Ian Welby.
"I am pleased that it has now been
shown that neither parasite is a major threat
to fisheries. More importantly, this should
instil greater confidence in the Category
2 list and that the remaining parasites
are on the list for good reason."
Fish infected with Category 2 parasites
can, currently, only be stocked into fully
enclosed waters where they cannot escape
to the wider environment. The Agency had
adopted this precautionary position in absence
of sound evidence that these parasites do
not pose a threat.
"The decision to remove the two parasites
from the list means the presence of either
parasite in a health check will no longer
be grounds for refusing a Section 30 consent
to stock in open waters such as rivers,
canals and unenclosed still waters,"
continued Paul Lidgett.
"We have estimated the value of the
fish with the parasite now allowed to be
stocked is about £500,000 per annum.
The change will come into effect on September
1, 2007, giving the industry time to adjust
before the next coarse fish stocking season.
Not only is the decision good for fish suppliers,
it also allows the Environment Agency to
focus on the more significant threats."
Carl Francis of Mainstream Fisheries and
the Coarse Fish Farmers and Traders Association
agreed with the decision, saying: "The
Coarse Fish Farmers and Traders Association
welcome the news the Environment Agency
has reviewed the status of these parasites
on the basis of science and consider they
are not a threat to fisheries. A decision
which reaffirms the policy of the Agency
to maintain movement restrictions, where
possible, only on those parasites which
are demonstrated to be harmful."
Mike Heylin, of the Fisheries and Angling
Conservation Trust, also agreed. "As
we have seen with Koi Herpesvirus, new and
emerging fish diseases can pose a real threat
to fisheries in England and Wales. It is
essential we focus our efforts on the parasites
that really count."
Further information can be found at www.efishbusiness.co.uk.
