Mackerel

Northeast Atlantic mackerel are below safe biological levels and there is no precautionary recovery plan in place. Therefore, it receives a critical fail for stock status and is a default red rating.

Stock assessments are carried out annually by the International Council for the Exploration of the Sea (ICES). The most recent assessment was published in 2025 using data up to the same year. The next assessment is expected in 2026.

The stock assessment defines reference points for fishing pressure (F) and biomass (B). For fishing pressure, there is a target to keep F at or below Maximum Sustainable Yield (MSY). For biomass, there is no target. However, there is a trigger point (MSY BTrigger). Below this level, F should be reduced to allow the stock to increase. Because BMSY is not defined, the Good Fish Guide applies its own definition of 1.4 x MSY BTrigger.

A benchmark assessment was held in 2025 and reference point values for the mackerel stock were adjusted.

Mackerel has been fished for centuries in the northeast Atlantic. Catches averaged 680,000 tonnes in the 1980s and 1990s, although they are thought to be under-reported during this time. Catches peaked at 1.4 million tonnes in 2014, and the recent average is around 1 million tonnes.

Spawning-stock biomass (SSB) was close to its lowest safe biological limits (Blim: 2 million tonnes) during the late 1990s and early 2000s, the population was recovering until 2015 when the populations began to decline. This decline has continued and the estimated 2025 SSB (2,740,823 tonnes) was 10% below Blim (3,067,017 tonnes).The stock is therefore in a very overfished state, and suffering reduced reproductive capacity.

Fishing pressure (F) exceeded upper limits during the early 2000s and then declined. It was below the level associated with Maximum Sustainable Yield (FMSY, 0.191) between 2011 and 2020, but has since increased. The estimated total catch in 2024 was 897,701 tonnes. F in 2024 was 0.27, which is 41% above FMSY. Therefore, fishing mortality is above target levels and the stock is not being harvested sustainably.

ICES advises that when the MSY approach is applied, catches in 2026 should be no more than 174,347 tonnes. This is a 70% decrease on the previous year's advice due to the decline in stock size, this advised reduction of fishing pressure is to achieve a 50% probability of SSB being above Blim in 2027 and the change in the perception of the stock after the benchmark.

Catch data for 2021 and 2022 for the Russian Federation was estimated, but there is confidence in the estimates.

Catch and survey data from recent years indicate that the stock has expanded north-westwards during spawning and the summer feeding migration. The change may be linked to changes in food availability, increased water temperature, and / or increased stock size.

Handlining for mackerel in the southwest UK is controlled by management measures that keep catches at low levels and protect juvenile mackerel.

For the Northeast Atlantic fishery in general, management is inadequate. The stock is fished by numerous countries and there is no agreed management plan to prevent overfishing. Catches have been consistently higher than scientific recommendations, and the stock is declining. However, in southwest England, there are a number of controls on fishing.

The handline fishery has a ring-fenced quota that is a very small proportion of total catches. In 2025, this allocation was 1,145 tonnes. It is specifically for the South West handline fishery, covering landings by vessels fishing for mackerel by handline in ICES areas 7e, f, g and h. Of the total combined TACs for the whole mackerel stock in 2025 (760,714 tonnes), this handline fishery accounts for 0.15%.

In addition, juvenile mackerel are protected within an area known as the Mackerel Box, where there are important nursery grounds. The Box was set up in 1981 and subsequently extended. It stretches roughly from the tip of the Pembrokeshire coast, west towards southeast Ireland, south to beyond the Scilly Isles, east to the Channel Islands, and north to the west Dorset coast. In this area, targeted fishing for mackerel by trawlers with net mesh sizes of less than 80mm, or any purse seiners, is prohibited. The exception is where mackerel makes up 15% or less of the total catch. Static nets and handlines are allowed. A 2002 review of the Mackerel Box by ICES concluded that it is an important tool in protecting juvenile mackerel.

There is a Minimum Conservation Reference Size of 20cm. Below the MCRS, fish cannot be sold for human consumption. Under the EU Landings Obligation (LO) and UK law, it is illegal to discard unwanted (e.g. undersized or over-quota) mackerel at sea. Discarding of unwanted mackerel catches is known to take place at low levels, estimated to be less than 1% of the total catch. Discarding of small mackerel has historically been a major problem in the mackerel fishery and was largely responsible for the introduction of the Mackerel Box.

The EU and UK both have fishery management measures, which can include catch limits, population targets, and gear restrictions. However, compliance in the EU and UK has been inconsistent, with ongoing challenges in implementing some regulations. The goal of reaching Maximum Sustainable Yield (MSY) by 2020 was missed, with less than half of UK TACs in 2024 following ICES advice. In 2024, the EU and UK reaffirmed their commitment to sustainable fisheries by aligning management with scientific advice to gradually approach MSY. However, no new target date has been set for achieving MSY across all fisheries.

The Marine Conservation Society views Remote Electronic Monitoring (REM) with cameras is one of the most cost-effective tools for providing reliable fisheries data and aiding informed management decisions. Fully monitored fisheries enhance collaboration, data accuracy, stock recovery, and reduce impacts on marine wildlife and habitats. However, the full potential of REM may only be achieved when it tracks fishing location and documents catch and bycatch, particularly where vulnerable species and habitats are at risk. As of January 2024, the EU is introducing a Remote Electronic Monitoring (REM) mandate for EU vessels, including CCTV cameras on vessels 18m or more that pose a potential risk of non-compliance, within the next 4 years. Across the UK, different approaches to REM are being taken and legislation is expected to be in place across all 4 countries within the next few years.

The Fisheries Act (2020) requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) in the UK. 43 FMPs have been proposed and are at various stages of development and implementation, these should all be published by the end of 2028. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. It is also essential the UK governments define and adopt a standardised approach or model across the four nations to a universally defined FMP design, to ensure the consistence, quality and coherence of all the proposal FMPs.

The Marine Conservation Society is keen to see publicly available Fishery Management Plans for all commercially exploited stocks, especially where stocks are depleted, that include:

• An overview of the fishery including current stock status, spatial coverage, current fishing methods and impacts
• Targets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidence
• Timeframes for stock recovery
• Improved data collection, transparency, and accountability, supported by technologies such as Remote Electronic Monitoring (REM)
• Consideration of wider environmental impacts of the fishery, including habitat impacts and minimising bycatch
• Stakeholder engagement

A Northern Shelf Mackerel FMP has been proposed, coordinated by the Marine Directorate that incorporates this stock. At the time of writing, it is too soon to know whether proposed management measures will be effective in managing the stock. For more information about this FMP and expected progress and timelines, see [https://www.gov.uk/government/collections/fisheries-management-plans#published-fmps].

For more detailed information about the Cornish handline mackerel fishery, visit the Cornwall Good Seafood Guide

A very small proportion of mackerel is caught by handlining. This is a low impact method, as there are no habitat impacts and bycatch can be released alive.

Most mackerel (around 71%) is caught by pelagic trawling, with purse seining making up most of the rest at around 28%. Only a small amount (1%) is caught by other gears, such as handlining.

In the southwest UK, the handline fleet operates in a restricted area known as the Mackerel Box. In this area, other fishing gears are restricted to protect juvenile mackerel. The handline fleet has a restricted quota, which is allocated to members of the Southwest Handline Fishermen's Association (SWHFA).

The fleet fishes by lowering a line of 25-30 hooks into the water which is then moved up and down in the water, before being pulled in. SWHFA uses brightly coloured feathers or plastic tubing to attract the mackerel, rather than bait. This means there are no concerns about the use of baitfish, which can sometimes put pressure on other wild fish stocks.

Handlining tends not to touch the seabed, meaning there is little or no risk of habitat damage. When the line is pulled in, unwanted catch can be released alive, meaning bycatch is rare.

For more detailed information about the Cornish handline mackerel fishery, visit the Cornwall Good Seafood Guide