Satellite imagery has allowed researchers from the University of Queensland to map the world’s intertidal zones. Their study has shown that global foreshore environments declined by up to 16% between 1984 and 2016.

The intertidal zone is a delicate ecosystem, vulnerable to climate change, erosion, and development.

Climate change

Plants and animals living in the intertidal zone are particularly vulnerable to climate change.

The intertidal zone is a harsh environment, and many species are already living at the extremes of their tolerance. Changes in air temperature, rainfall and ‘storminess’, as well as sea level rise and changes in water temperature and acidity, can have a devastating effect on species and ecosystems.

Coastal squeeze

‘Coastal squeeze’ is a term used to describe the damage to, or loss of, habitats caused by man-made structures or actions that prevent the landward movement of these habitats in response to sea-level rise or an increase in storms.

In a natural system, as sealevels rise, coastal habitats, such as saltmarsh, naturally move further inland. The construction of a seawall stops this from happening and the coastal habitat is ‘squeezed’ as the seaward edge is eroded.

Development

Flat coastal areas, such as the Gwent Levels, are particularly vulnerable to development, such as housing, industry and power generation. The development of tidal power generation schemes in the estuary could have a devastating effect on the intertidal zone.