Zoo-sanitary risks associated with trade and transfer of fish eggs and sperm
European Network for the Dissemination of Aquaculture
RTD Information (Q5CA-2000-30105) and previously FAIR-3837, Aquaflow ref. :
TL2003-151
The trade in fertilised eggs and gametes for finfish
aquaculture is generally subject to strict zoo-sanitary regulations and
certification requirements. However, many of these are based upon sometimes
old and rather frequently scarce scientific data. The aim of this ongoing
project is to re-assess and scrutinise the scientific basis for current
zoo-sanitary control requirements. The quantification of risks for
transferring certain infections when moving eyed eggs and fish sperm, and
the potential of new techniques for improving the efficacy of disease risk
management will be especially addressed.
During its first meetings, the project group has
selected ten infections for in-depth scrutiny. These are Infectious
haematopoietic necrosis; Viral haemorrhagic septicaemia; Spring viraemia of
carp; Infectious salmon anaemia; Epizootic haematopoietic necrosis; Viral
Encephalopathy and Retinopathy/Viral Nervous Necrosis; Infectious pancreatic
necrosis; Bacterial kidney disease (Renibacterium salmoninarum);
Flavobacterium psychrophilum infections and Piscirickettsiosis (Piscirickettsia salmonis).
An early objective was to establish the evidence –
or lack of it – that vertical transmission does actually occur and in
particular if transmission may occur inside the fertilised egg (“true
vertical transmission”) or only as contamination of the egg surface,
seminal fluids or sperm. The
results suggest that evidence for true vertical transmission has been
presented for BKD, IPN and Piscirickettsiosis, whereas experimental and
field studies suggest that vertical transmission of VHS, IHN and ISA may be
effectively prevented by common egg disinfection procedures.
For several of the listed diseases, there is a lack of published
information.
Further work to be completed includes quantitative
risk assessment; a review on pathogen survival and disinfection, and a
review on the quality of diagnostic tests applicable to parental fish,
sexual products including gametes, or embryos. The project partners and
future reports may be consulted at www.veso.no/fisheggtrade.
For more information, contact:
MIDTLYNG Paul J.
VESO A/S
Ullevålsveien 68 PO Box 8109 Dep.
NO - 0032 Oslo
Norway
Phone : +47 22 961120
Fax : +47 22 961101
e-mail: paul.midtlyng@veso.no