Ecosystem Dynamics and Fisheries Management in the Baltic Sea

The Baltic Sea constitutes a semi-enclosed brackish basin with pronounced salinity and temperature gradients that shape its ecological communities. Nutrient inputs from agriculture and urban sources drive eutrophication, leading to recurrent hypoxia in bottom waters and habitat compression for benthic organisms. These changes cascade through the food web, affecting mesozooplankton, forage fish such as herring and sprat, and top predators including the commercially important Atlantic cod. Overfishing, habitat degradation and climate-induced stressors have jointly undermined the resilience of fish stocks. Ecosystem-based management approaches have been adopted to integrate water-quality measures, adaptive catch quotas and spatial protection into policy frameworks. At the regional scale, coordinated actions under multilateral agreements aim to reduce nutrient loads, restore oxygen conditions and secure sustainable yields. Advances in modelling tools now enable scenario testing of combined management and climate interventions, enhancing decision support for stakeholders. This integrated perspective highlights the global significance of Baltic sea-level change as a model for marine governance under multiple human pressures.

Research from Nature Portfolio

Recent experimental work has explored how juvenile Atlantic cod respond physiologically to simultaneous warming, ocean acidification and freshwater inputs. Multi-stressor trials revealed genotype-dependent responses: coastal ecotypes exhibited greater tolerance and lower oxidative stress than offshore conspecifics under identical conditions. These findings underscore the importance of recognising intraspecific variation when setting recovery targets and designing fisheries regulations, as ecotype-specific resilience may inform selective restocking and adaptive harvest strategies.

Ecosystem Dynamics and Fisheries Management in the Baltic Sea publication trend

The graph below shows the total number of articles in ecosystem dynamics and fisheries management in the baltic sea across all publications each year (not limited to Nature Index journals).

Technical terms

Eutrophication: Enrichment of water by nutrients, leading to excessive algal growth and oxygen depletion.

Hypoxia: Low dissolved-oxygen conditions in bottom waters that compress habitable zones for marine life.

Ecotype: A genetically distinct population within a species adapted to specific environmental conditions.

Ecosystem-based management: An integrated approach that considers entire ecosystems, including human impacts, to guide resource use and conservation.

Trophic interactions: Feeding relationships among organisms that determine energy flow and community structure.

References

1. Physiological responses of Atlantic cod to climate change indicate that coastal ecotypes may be better adapted to tolerate ocean stressors. Scientific Reports (2024).
2. Ecosystem Services of the Baltic Sea—State and Changes during the Last 150 Years. Environments (2024).
3. Changes in Atlantic climatic regulation mechanisms that underlie mesozooplankton biomass loss in the northern Baltic Sea. Heliyon (2024).
4. Spatial distribution projections of suitable environmental conditions for key Baltic Sea zooplankton species. Limnology and Oceanography (2024).