Paleoenvironmental Changes in Coastal Marine Systems

Coastal marine environments have undergone dynamic transformations throughout the Holocene and earlier epochs in response to sea-level fluctuations, sediment supply variations, climate oscillations and tectonic adjustments. Sediment cores, microfossil assemblages and geomorphological features such as beach ridges, strandplains and cheniers serve as archives of past conditions, recording shifts between fluvial-dominated and wave-dominated regimes, changes in salinity and water energy, and the imprint of ocean–atmosphere interactions. Global case studies—from the progradation of large deltas to subtle changes in sub-Antarctic shelves—demonstrate that minor climatic perturbations can trigger significant reorganisation of coastal systems, with implications for habitat distribution, carbon cycling and human settlement patterns. Understanding these past dynamics is crucial for refining models of future sea-level rise and informing sustainable coastal management in regions vulnerable to erosion, flooding and ecosystem loss.

Research from Nature Portfolio

One foundational study reconstructed a continuous 6 000-year record of coastal-ridge succession in a major delta, revealing an approximately eleven-year cycle in ridge formation that aligns with solar activity patterns. Through detailed stratigraphic and sedimentological analyses, this work identified alternating phases of wave-dominated and fluvial-dominated deposition, driven by shifts in wind strength and broader glacial–interglacial climate cycles. The findings underscore the sensitivity of deltaic systems to subtle temperature and wind-driven changes, and show how minor cooling intervals can dramatically alter sediment dispersal and ecosystem productivity.

Paleoenvironmental Changes in Coastal Marine Systems publication trend

The graph below shows the total number of articles in paleoenvironmental changes in coastal marine systems across all publications each year (not limited to Nature Index journals).

Technical terms

Palaeoenvironmental proxy: A natural recorder of past environmental conditions, such as microfossil assemblages, geochemical signatures or geomorphic features.

Coastal ridge: A linear accumulation of sand or gravel formed by wave action and beach processes, often marking former shoreline positions.

Strandplain: A broad, prograding coastal feature composed of closely spaced beach ridges and swales extending inland from the active shoreline.

Foraminifera: Marine protozoans with calcareous shells whose assemblages reflect past salinity, temperature and nutrient conditions.

Neritic zone: The shallow marine area above the continental shelf, typically extending to depths of around 200 m, where sunlight penetration supports abundant life.

References

1. Climate changes and solar cycles recorded at the Holocene Paraná Delta and their impact on human population. Scientific Reports (2015).
2. Benthic foraminifera diversity from the south Atlantic Ocean: Tierra del Fuego and surrounding waters (South America). Anais da Academia Brasileira de Ciências (2024).
3. Palaeoenvironmental changes based on foraminifera during the late Holocene at the Beagle Channel, Argentina. Anais da Academia Brasileira de Ciências (2022).