Migration Ecology of Estuarine Fishes

Estuarine fishes exhibit a spectrum of migratory strategies shaped by physiological tolerances, life-history traits and dynamic environmental gradients. Many species perform seasonal movements between rivers, estuaries and the continental shelf to access spawning sites, feeding grounds and refuges from unfavourable conditions. Anadromous taxa ascend freshwater to reproduce before returning to brackish waters for growth, while other species display catadromous or facultative migrations, in which only a subset of the population moves according to size, energy reserves or habitat cues. Key drivers include salinity shifts, thermal regimes, prey availability and hydrodynamic forces that regulate timing and routes. Advances in acoustic telemetry, biophysical modelling and habitat mapping have revealed fine-scale movement patterns and the importance of estuarine turbidity maxima as nursery and foraging hotspots. Research on model organisms such as striped bass and Japanese seaperch has elucidated size-dependent departure thresholds, multiple spawning contingents and demographic consequences of partial migration. Integrating behavioural, physiological and ecosystem-scale approaches enhances our ability to predict distributional shifts, guide ecosystem-based fisheries management and develop adaptive conservation measures in the face of climate change and habitat alteration.

Research from Nature Portfolio

Recent studies have demonstrated facultative coastal evacuations by estuarine residents during extreme weather events. Broad-scale acoustic tracking revealed that intense storms can trigger atypical downstream migrations, with fish departing estuaries when rapid drops in salinity, temperature and dissolved oxygen occur. Subsequent exploratory trips back into the estuary suggest individuals assess habitat recovery before settling, highlighting behavioural plasticity that underpins resilience to climatic disturbances and emphasising the need to maintain unobstructed corridors for evacuation and return.

Migration Ecology of Estuarine Fishes publication trend

The graph below shows the total number of articles in migration ecology of estuarine fishes across all publications each year (not limited to Nature Index journals).

Technical terms

Anadromy: Life-history strategy in which fish migrate from marine or estuarine environments into freshwater to spawn.

Catadromy: Life-history strategy in which fish migrate from freshwater into marine or estuarine environments to feed and grow.

Facultative migration: Opportunistic movement behaviour in which only some individuals migrate in response to environmental or physiological triggers.

Partial migration: Population structure in which migratory and resident forms coexist within the same species.

Acoustic telemetry: Tracking method using coded sound signals to monitor individual fish movements in aquatic environments.

Spawning run contingent: Group of individuals within a population that share a common timing or route of reproductive migration.

References

1. Coastal evacuations by fish during extreme weather events. Scientific Reports (2016).
2. Differential migration in Chesapeake Bay striped bass. PLOS ONE (2020).
3. Multiple spawning run contingents and population consequences in migratory striped bass Morone saxatilis. PLOS ONE (2020).
4. An Eulerian perspective on habitat models of striped bass occurrence in an offshore wind development area. ICES Journal of Marine Science (2024).