New scientific survey results show high biomass levels for several small pelagic fish stocks in the Northeast Atlantic, including anchovy and sardine. The findings come from coordinated acoustic and egg surveys carried out in 2025 across waters from the Gulf of Cadiz to the Celtic Sea.
The surveys are part of the ICES Working Group on Acoustic and Egg Surveys for Small Pelagic Fish (WGACEGG), which compiles data used in stock assessments for key pelagic species.
Anchovy biomass reaches record levels in some areas
Anchovy biomass remained high in Iberian waters. In ICES Division 9a, survey data show a general increase since 2016, with abundance and biomass in 2025 reaching the highest levels recorded in the time series.
In the Gulf of Cadiz autumn survey, scientists estimated around 4.34 billion anchovies with a biomass of 51,608 tonnes. This represents a 38% rise in abundance and a 105% increase in biomass compared with the previous year.
Researchers also observed a strong contribution from young fish. Age-0 anchovies made up 58% of the total population in the survey area.
Sardine biomass rises sharply
Survey results also indicate a marked increase in sardine biomass in several areas.
Record-high abundance was observed in ICES divisions 9a, 8abc and 7ef, according to the report.
These results suggest strong recruitment and favourable conditions for sardine populations in parts of the Northeast Atlantic.
Mixed picture for other pelagic species
The surveys covered a wide range of small pelagic species, including sprat, horse mackerel, mackerel, blue whiting and boarfish.
Horse mackerel abundance was reported as above average across surveyed areas. At the same time, sprat densities were below average in the Bay of Biscay but higher in northern Scottish waters.
Blue whiting densities were mostly close to average, with higher concentrations west and north of Ireland.
Surveys cover a wide Atlantic shelf area
The coordinated survey programme combines acoustic measurements and egg-production methods to estimate the biomass and distribution of small pelagic fish.
In 2025, multiple spring and autumn surveys provided near-synoptic coverage of the shelf seas from southern Iberia to Irish and UK waters.
The data feed directly into ICES stock assessments and fisheries advice for pelagic fisheries in European waters.