Economic importance of proliferative kidney disease of salmonid fish in England and Wales
Clifton-Hadley, R.S.; Bucke, D.; Richards, R.H.
Veterinary Record 119(12): 305-306
1986
ISSN/ISBN: 0042-4900 PMID: 3776035 Document Number: 274513
A previous survey in 1981 indicated that 20 of 45 salmonid fish farms in England and Wales were positive for proliferative kidney disease, and since then another 25 have been identified and a further 20 suspected of being infected. There are also another 77 farms on rivers and their tributaries which supply positive sites, giving a total of at least 142 farms directly at risk of a total of about 400 salmonid farms supplied by river water in England and Wales. Total annual production from the 45 affected farms is about 3240 tonnes. If mortality on the 45 farms averaged 5-10%, the annual loss would be 160-320 tonnes of fish equivalent to #240 000-#480 000 at current wholesale prices. If the ratio of food conversion is deteriorated from 1.5:1 to 2.0:1 on 3240 tonnes of fish produced, the economic loss would be #640 000 a year assuming an average food cost of #400/tonne. As these estimates are confined to farms with histologically confirmed disease, a conservative figure for losses throughout England and Wales is #1 million a year.