Introduction

Background

Statistics on salmon stocks and fisheries are compiled jointly by staff from the Centre for Environment, Fisheries and Aquaculture Science (Cefas) Salmon and Freshwater Team, as well as fisheries personnel from the Environment Agency and Natural Resources Wales/Cyfoeth Naturiol Cymru. The statistics present the status of salmon stocks and fisheries in England and Wales, including information on stock levels, catches and exploitation rates. These data are not published as official statistics, although all three organisations are classed as official statistics producers under the Statistics and Registration Service Act (2007), or are named in secondary legislation.

These statistics are collated annually to assist the International Council for the Exploration of the Sea (ICES) in providing scientific advice to the North Atlantic Salmon Conservation Organisation (NASCO). They also enable the UK and Welsh governments to set conservation limits, targets and fishing byelaws for salmon rivers and inform fishery managers and anglers.

The producer organisations are currently undertaking a review to evaluate the existing methodology for assessing salmon stocks, which forms the basis of the statistics. The review will include a public consultation in 2026 and may cover technical aspects such as rod exploitation rates, estimation of effort ratios and egg deposition rates. While the precise scope of the proposed methods review is still uncertain, some detail on its potential scope is noted in the supporting guidance to the statistics . A separate formal review by the Environment Agency is expected to consider the associated compliance schemes related to setting conservation limits, targets and fishing byelaws for salmon rivers and to support policy decisions ahead of the expiry of the current byelaws in 2028. This will follow an initial informal review which concluded in October 2025.

Why we did this review

The Office for Statistics Regulation (OSR) carried out an initial review of these statistics in 2022 following concerns raised with us by users of the statistics. These users’ concerns focused on the producers’ lack of communication around their longstanding plans to review the estimation methods, which were first set out in 2004. At the time, we recommended that the producers consult their sponsoring departments for support to engage with users during the process of updating the estimation methods. We also recommended that the producers improve transparency around the timeline for implementing the plans, and that they improve the accessibility of supporting documentation, particularly for more technical elements, such as rod exploitation rates.

In 2024, the statistics producers announced their intention to consult publicly on proposed changes to methods and reporting in 2025, with the consultation subsequently delayed to 2026. In discussions with the statistics producers in 2025, and in light of their plan to consult publicly, we agreed to carry out a further review of the statistics’ compliance with the Code of Practice for Statistics (the Code). The purpose of this second review is to provide advice, support and recommendations to help the producers manage these changes in line with the Code, to support user confidence in the statistics during the period of change, and to maximise the value of future improvements.

As such, this review has focused on the three broad areas that will be central to ensuring the planned changes are developed, communicated and delivered in line with the Code:

• Changes to methods: How users and stakeholders have been informed of the proposed changes to methods and of their potential impact on the statistics; how users have been assured that the proposed methods are sound and represent the best available estimates; and the opportunities for users to feed into decision-making on methods.
• Changes to reporting: How users and stakeholders have been considered in the proposed changes to reporting; how they have been informed about the changes and assured that their needs will continue to be met; and how outputs will be accessible and provide clear insights that serve the public good.
• Institutional governance and statistical leadership: How decision-making processes are enacted; and the transparent and orderly release of statistics.

While this review has focused on statistics on salmon stocks and fisheries in England and Wales, several of our findings and recommendations also apply more broadly to statistical practices at an organisational level.