Climate Impact on Small Pelagic Fish Dynamics

Small pelagic fishes, including sardines, mackerels and sauries, are pivotal in marine food webs and support major fisheries worldwide. Their populations are highly sensitive to variations in ocean temperature, current regimes and primary productivity, all of which are undergoing rapid change under global warming. Rising sea surface temperatures can shift thermal habitats poleward, alter stratification and modify plankton communities, with cascading effects on distribution, growth and recruitment of pelagic stocks. Variability in large‐scale currents, such as the Oyashio and Kuroshio, influences nutrient upwelling and prey availability, driving interannual fluctuations in abundance and catch locations. Predictive models integrating environmental indices, satellite observations and bioenergetics frameworks have improved understanding of how climate drivers shape migration routes, spawning habitats and population resilience. These advances are informing adaptive management strategies that aim to anticipate range shifts, safeguard nursery grounds and ensure sustainable exploitation in a changing ocean.

Research from Nature Portfolio

Recent studies have quantified the relative influence of oceanographic factors on the distribution and migration of a key small pelagic species in the North Pacific. By associating monthly catch‐per‐unit‐effort with concurrent measurements of sea surface temperature, chlorophyll‐a concentration, salinity, mixed layer depth and eddy kinetic energy, researchers demonstrated that temperature anomalies and mesoscale eddies strongly modulate habitat suitability and fishing ground formation. Statistical approaches revealed dome‐shaped responses of abundance to chlorophyll and salinity, while elevated eddy activity and cooler waters of the Oyashio intrusion triggered northward or coastal shifts in migration. These findings elucidate mechanistic links between physical ocean variability and stock dynamics, offering refined forecasts of seasonal abundance hotspots.

Climate Impact on Small Pelagic Fish Dynamics publication trend

The graph below shows the total number of articles in climate impact on small pelagic fish dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Catch‐per‐unit‐effort (CPUE): A standardised index of fish abundance derived by relating catch weight to fishing effort, used to monitor population trends.

Sea Surface Temperature (SST): The temperature of the ocean’s surface layer, a key driver of metabolic rates, distribution and spawning success in pelagic fishes.

Habitat Suitability Index (HSI): A composite metric that integrates environmental variables to estimate the capacity of a region to support a given species’ life stages.

Bioenergetics Model: A mathematical framework that simulates an organism’s energy intake and expenditure to predict growth, reproduction and survival under varying environmental conditions.

References

1. Effects of oceanographic environment on the distribution and migration of Pacific saury (Cololabis saira) during main fishing season. Scientific Reports (2022).
2. Enhancing Chub Mackerel Catch Per Unit Effort (CPUE) Standardization through High-Resolution Analysis of Korean Large Purse Seine Catch and Effort Using AIS Data. Sustainability (2024).
3. Spatio-Temporal Variability of the Habitat Suitability Index for Chub Mackerel (Scomber Japonicus) in the East/Japan Sea and the South Sea of South Korea. Remote Sensing (2018).
4. Evaluating the influence of environmental factors on the early life history growth of chub mackerel (Scomber japonicus) using a growth and migration model. Progress In Oceanography (2022).