Atlantic Mackerel Survey 2025

Publisert den 16.07.2025 av Per Arne Fagervoll Meek

Mid-Season Update from the Norwegian Sea

Each summer, the Norwegian Sea becomes the stage for one of the most significant pelagic research operations in the Northeast Atlantic: the annual Makrelltokt (Mackerel Survey). Conducted jointly by Norway, the Faroe Islands, Iceland, and Greenland, the survey aims to chart the abundance, distribution, and biological characteristics of Northeast Atlantic mackerel (Scomber scombrus). The results are critical inputs for stock assessments coordinated by ICES and inform sustainable management of one of Europe?s most valuable fisheries.

Objectives of the Makrelltokt

• Estimate stock size and biomass
• Map spatial distribution across key oceanic zones
• Collect biological data: length, weight, age, maturity
• Record environmental parameters: temperature, salinity, zooplankton abundance
• Detect shifts in species composition and ecosystem changes

Survey Design and Progress in 2025

The 2025 Makrelltokt involves several research vessels, with coordinated survey effort to cover both southern and northern sectors of the Norwegian Sea and adjacent waters:

Preliminary Results for 2025

Catch Rates and Distribution

So far, average mackerel catches per 30-minute trawl in surveyed areas are on par with 2024 levels, suggesting relative stability in local mackerel abundance. However, survey scientists emphasize that:

?It is still too early to provide a reliable estimate for the total mackerel stock, as large parts of the Norwegian Sea remain to be surveyed.?
? Havforskningsinstituttet (Institute of Marine Research), July 2025

Spatially, the mackerel have shown a familiar distribution pattern, concentrating in the central Norwegian Sea rather than the nearshore southern regions.

Bycatch Observations

• Juvenile Salmon: A single trawl contained 38 juvenile salmon, measuring 21?27?cm. Species identification is underway to confirm whether they are Atlantic salmon (Salmo salar) or invasive pink salmon (Oncorhynchus gorbuscha).
• Atlantic Saurel (Makrellgjedde): One trawl recorded a remarkable 250 individuals of Atlantic saurel (Trachurus trachurus), a southern species rarely seen this far north.

Biological Measurements: Size and Weight

Although 2025-specific size and weight data are not fully published yet, historical data provide an informative baseline:

Environmental Data Collection

At each station, researchers collect water temperature, salinity, and zooplankton biomass, critical for understanding ecosystem influences on mackerel behavior and distribution.

Broader Ecosystem Surveys

Parallel to mackerel trawl sampling, the survey integrates acoustic monitoring of Norwegian spring-spawning herring (Clupea harengus) and horse mackerel (Trachurus trachurus).

Comparison with Previous Years

The preliminary impression from 2025 is one of continuity rather than major change. However, recent years have shown fluctuations:

• In 2024, a roughly 42% decrease in total biomass was recorded compared to 2023, though the stock remained within safe biological limits.
• Earlier years (e.g. 2018) observed mackerel expanding farther west and north, possibly due to ocean warming and shifting prey fields.

Next Steps

• Survey completion in early August 2025
• Data analysis for updated stock indices and biomass estimates
• Incorporation into ICES advisory processes for 2026 quotas

Technical Summary Table

Charts and Visuals