GIS maps of
intertidal zones in Singapore
About Intertidal Zones
Located at the junction of the atmosphere, hydrosphere, and lithosphere, the intertidal zone is where air, earth, and land interact. It is a zone between high tide and low tide where an abundance of marine life thrives. Unfortunately, it's a place where changes to the climate or human impact make their greatest impact.

Littoral Zonation The intertidal zone is further divided into four key zones
a diagram of the four key zones

Lower intertidal zone - dry only during the lowest tides and contains the highest biodiversity within the inter tidal zone.
Middle intertidal zone - regularly covered with sea water.
Upper intertidal zone - covered by water during high tide so it experiences dry periods daily.
Spray zone - the "desert" of the inter tidal zone, this area survives on the mist and spray of the ocean.

Significance of these zones

Spray Zone - Wave-spray nourishes life here. This zone could be considered the "desert" of the intertidal community.

Upper Intertidal Zone - Sea water reaches this zone only during high tides. Here, you will find life that regularly survives two long droughts each day. Limpets survive by feeding on algae. They suction their shells tight to rocks for protection from the waves and sun. Sea lettuce and other marine algae thrive in this extreme zone.

Middle Intertidal Zone - Sea water regularly floods this zone.

Lower Intertidal Zone
- This zone becomes dry only during the lowest tides. The intertidal's greatest diversity of life thrives in this stable region.

by Dr. D. Kumaran Raju,
Research Fellow, Marine Information Technology Laboratory
Tropical Marine Science Institute
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