Intertidal ZonesBy. Ms. Messer

Intertidal Zone

Where in the world is it found?

Intertidal zones are found where the land and sea meet, between the high and low tide zones. This complex marine ecosystem is found along coastlines worldwide.

Intertidal Zone Abiotic Factors

Because of tides, there are huge daily changes in moisture, temperature, turbulence (from the water), and salinity (amount of salt).

This biome is rich in nutrients and oxygen.

Native Plants

Native Plants

Seagrasses are grass-like flowering plants that live completely submerged in marine and estuarine waters.

Marine algae is also known as seaweed and comes is hundreds of varieties.

Native Animals

Native Animals

The sea anemone is a predatory animal that looks like a flower and lives on the ocean floor.

Bivalves are soft-bodied animals that are protected by two hard shells, hinged together. Scallops, oysters and clams are bivalves.

Hermit crabs are crabs that lack a hard shell; they use a discarded shell for protection.

Plant Adaptations

Many plants can adapt to varying levels of salt in the water and high changes in temperature that happen every day.

Animal Adaptations

Most intertidal animals have a hard outer shell or exoskeleton to ensure they aren’t crushed by the rough tides.

Symbiotic Relationship in Intertidal Zones

Limpet (small clam-like organism) and coralline crust algaeThe limpet gets a constant source of food and a

smooth surface to feed from. The algae benefits by having its surface cleaned by the limpet. Without the limpet, coralline crust algae would suffocate under debris and faster growing algae would overtake its space. This is an example of mutualism.

Where’s the party? There are LOTS of recreational activities here!

If you’re looking for fun, come to the intertidal zone!

If you want to see a unique marine ecosystem with tons of critters, you’ve come to the right spot. Unfortunately, people have negatively impacted this biome with direct pollution and introduction of invasive species. Most intertidal zones are protected areas or nature preserves that people can’t disturb.

Famous Intertidal Zones

Glacier Bay, Alaska Intertidal Zone

Bodega, California Marine Reserve

Gulf Island, British Columbia National Park Preserve

Environmental Threats

Visitors: People are one of the biggest threats to the intertidal zone, as tide pools are popular attractions. The overall impact of people exploring tide pools and stepping on organisms and their habitat, and sometimes taking creatures, has resulted in a decrease in organisms in some areas.

Coastal Development: Pollution and runoff from increased development can damage tide pools through the introduction of contaminants.

Endangered Species

Triton Trumpet Snail

Why should we care?

Although intertidal zones represent only a very small proportion of the Earth's surface, they're important because they're regions in which two very different types of environment meet, and in which a complex web of interactions takes place.

Rocky intertidal shores support an enormous range of life. Rocky-shore animals and plants have an increasingly harder time the further they are from the sea, since they rely on seawater and most are unable to move with the tides. Seaweed thrives here and many animals survival is dependent on seaweed for food.