Salmon mortality related to anglers
Case reference EIR2026/49162
Received 13 October 2026
Published 14 October 2026
Request
What is the equivalent annual number of wild Atlantic salmon that would be potentially subject to post catch and release mortality, using the Environment Agency’s assumed post catch and release mortality rates, based on the EA’s Assessment of salmon stocks for the both the River Test and River Itchen.
Could you please provide the calculations used, explained in layman’s terms.
I would also ask that you detail the assumptions used, such as the mortality rates assumed.
I would request the information is separate for each river.
I would request the information is provided for the last 5 years of published Stock Assessments.
Response
I enclose the data as requested in relation to the number of wild Atlantic salmon potentially subject to post catch and release mortality on the Test and Itchen as used in the annual assessment of salmon stocks in England and Wales, for the above-mentioned rivers.
Please refer to the Open Government Licence which explains the permitted use of this information.
The table below contains the number of estimated adult Atlantic salmon lost to post catch and release mortality following rod and line angling on the River Itchen and River Test.
|
Year |
River Itchen |
River Test |
|
2021 |
13 |
20 |
|
2022 |
10 |
15 |
|
2023 |
11 |
15 |
|
2024 |
9 |
9 |
|
2025 |
7 |
11 |
Please find supporting narrative related to the calculation of these figures, in answer to each of the questions posed in the information request.
Could you please provide the calculations used, explained in layman’s terms.
A mortality factor of 20% is applied to the reported rod and line catch data for Atlantic salmon specific to each river. This 20% mortality factor is made up of 9% natural in-river mortality and 11% mortality attributed to post catch and release mortality. Natural in-river mortality refers to the number of salmon that die from natural causes from the time they arrive back in the river to the time they spawn. Post catch and release mortality refers to fish that have been died after the process of being captured by rod and line and subsequently released. The reported catch and release rate is 100% on both rivers, so this mortality does not refer to fish that are deliberately killed and retained as this practice does not take place on either river.
As such, the numbers presented in the table above represent 11% of the reported rod catch for each river, rounded to the nearest whole number.
I would also ask that you detail the assumptions used, such as the mortality rates assumed.
A post catch and release mortality rate of 11% is applied to river specific reported rod catch data. This is a standard mortality factor applied across all rivers in England and Wales as part of the annual assessment of salmon stocks in England. It is not river specific and does not consider the fishing method types used on each river.
I would request the information is separate for each river.
Please see table above.
I would request the information is provided for the last 5 years of published Stock Assessments.
Please see table above.
Documents
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