Question reference: S5W-35788
- Asked by: John Finnie, MSP for Highlands and Islands, Scottish Green Party
- Date lodged: 5 March 2021
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Current status: Answered by Fergus Ewing on 23 March 2021
Question
To ask the Scottish Government, further to the answer to question S5W-35256 by Fergus Ewing on 4 March 2021, in light of the comment by the cabinet secretary that the "information required to estimate the total number of sea lice in salmon farms each year is not held by the Scottish Government and therefore we cannot provide such an estimate", whether it will provide the information that it holds on which the cabinet secretary based his comment that "data on average number of sea lice per fish indicates a downward trend in recent years".
Answer
The data which Marine Scotland has analysed to determine the general trend in average sea lice numbers per fish in recent years is monthly data which has been published by the Scottish Salmon Producers Organisation via their website and which has been in the public domain. The full historic data set is no longer available on that media and therefore we will make our data set available on Marine Scotland’s NMPi website. Analyses of data has been published in two papers in relation to different time periods; ‘ Describing temporal change in adult female
Lepeophtheirus salmonis abundance on Scottish farmed Atlantic salmon
at the national and regional levels. L.M. Hall and A.G. Murray (2018) and A preliminary assessment of indirect impacts on aquaculture species health and welfare in Scotland during COVID-19 lockdown. Murray et al (2021).
The average sea lice numbers per fish per year can be summarised as follows:
Year | Average sea lice count |
2013 | 0.54 |
2014 | 1.15 |
2015 | 1.30 |
2016 | 1.33 |
2017 | 0.90 |
2018 | 0.612 |
2019 | 0.741 |
2020 | 0.623 |
Following the introduction of The Fish Farming Businesses (Reporting) (Scotland) Order 2020 on 29 March 2021, Aquaculture Production Businesses which farm fish (other than at freshwater sites) will be required to report average weekly female sea lice numbers per site per week, one week in arrears to Scottish Ministers. The data will be published in the interests of transparency. Ongoing analysis of sea lice data over a longer period of time will help provide a more accurate picture of sea lice trends.