Inspection reports

Case Number: 2023-0279

Download Site inspected despite temperature being above 14 degrees C as the site was last inspected in 2015.
This is the first cycle of rainbow trout and the first time the site has been used since 2015. Inherited all equipment from previous owners. Not all tanks on site are currently useable due to some tanks being damaged (leaky) or from the previous owners removing valves. Water inlet system has 3 filters and the outlet system has one large 60 micron drum filter.
Approx. 60,000 eggs came onto site 23/12/2021 from Houghton Springs in Dorset. Owner transported eggs in his own car so no official transport records. Owner has been advised to complete transport records and do this for any future movements onto or off of site including waste transfer notes. Currently morts are being frozen on site and moved to SSF by the owner for disposal on approximately a monthly basis.
The only significant health issue occurred at the beginning of the cycle (began 14th February 2022). Increased mortalities
(average >350 fish) occurred daily for the next two weeks – a total of 5,587 fish (9.31%). Fish were sac-fry at the time and so just fall below the reporting threshold for fish at this size. Treatment using formalin began on 28th February – 100ppm for 10 minutes. This was repeated for three days in a row and then fish were treated every Monday for 7 weeks with 200ppm for 10 minutes. Fish were then graded into different tanks. Over the course of the disease outbreak approximately 10,000 fish were lost. The delay in treatment was caused by a delay in identifying the problem as initially the owner believed the issue could have been food going off in the gut as the mortalities coincided with the start of first-feeding and heating of the tanks. No disease issues since and owner now does regular skin scrapings.
Mortality recording on Fish Talk began in April 2022 after the Costia outbreak (daily diary entries beforehand). Mortality of
2,505 fish since end of April 2022 to June 2023. Mortalities have either been runts or fish with swim bladder issues. Owner began to notice multiple fish swimming abnormally and histology tests were carried out. Results came in on 6/10/2022 with no significant findings although it was noted that some findings could be remnants of Costia. Vets believe these fish have a swim bladder abnormality which causes over inflation and could be a congenital issue. The issue only seems to cause mortality in the smaller fish.
Fish have only been vaccinated for enteric redmouth disease (immersion) under the vets advice.
Owner has concerns over fin issues despite the stocking density being well below the limit.
Fish are processed on site (whole fish, no gutting) and sold either locally in Orkney or in London.
On physical inspection of the site fish were in good health. A few fish with swim bladder issues were observed but keeping with the shoal and feeding well. Some fish had minor fin damage but nothing of concern.
Site is looking for approval to smoke fillets which will boost income and generate new business.
No current plan for the future. The site is currently having problems with water supply due to the unusual hot weather and the cost of electricity. At present the immediate plan is to empty the site and see how the financial situation is / the viability of having another cycle. [Original PDF]

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