Large blades of bull kelp in the ocean.

Plants & Algae

Seagrasses are flowering plants that can form dense underwater meadows and are an important shallow water habitat.

Seagrass Overview

Are you a student researching seagrass or someone looking to learn more about seagrass beds? This overview dives into everything to know.

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Featured Content

Close-up photograph of translucent coral polyps, showing the symbiotic algae living inside.

Zooxanthellae and Coral Bleaching

two mangrove trees in the crashing waves

Mangroves

Relatively slow moving, juvenile plane-head filefish Monacanthus hispidus (Monacanthidae) travel along with the algae. They pick off and eat small animals as they move around in the rotating sargassum ball. Adult filefish only grow to be about 11

A World Adrift: Life in the Sargassum

Many species of pink coralline algae, which cements coral reefs together, cover a reef surface in the Southern Line Islands.

Coralline Algae: The Unsung Architects of Coral Reefs

Seagrasses are flowering plants that can form dense underwater meadows and are an important shallow water habitat.

How Coastal Seagrass Feeds the Deep

Are You An Educator?

At Smithsonian Ocean, we have lesson plans, activities, and resources to help you engage your students in the wonders of our oceans.

see all lesson plans see plant & algae lesson plans

Plants & Algae Articles

Close-up photograph of translucent coral polyps, showing the symbiotic algae living inside.

Zooxanthellae and Coral Bleaching

California sea lions swimming

Sea Lion Sickness

An algal bloom, also known as a red tide, has converted the ocean's surf to a red color

Scientists Work to Predict and Prevent Algae Blooms

Screen shot of "Sea Grapes: A Google Earth Tour" with aerial view of the Earth in Google Earth.

Sea Grapes: A Google Earth Tour

This shrimp is colored to fit in - probably why they are common members of the seaweed community.

A World Adrift: Life in the Sargassum Slideshow

Relatively slow moving, juvenile plane-head filefish Monacanthus hispidus (Monacanthidae) travel along with the algae. They pick off and eat small animals as they move around in the rotating sargassum ball. Adult filefish only grow to be about 11

A World Adrift: Life in the Sargassum

two mangrove trees in the crashing waves

Mangroves

Intense volcanic CO2 vents in Ili Ili Bua Bua, Normanby Island, Papua New Guinea.

Will Coral Reefs Survive Acidification?

Seagrasses are flowering plants that can form dense underwater meadows and are an important shallow water habitat.

How Coastal Seagrass Feeds the Deep

Seagrasses are flowering plants that can form dense underwater meadows and are an important shallow water habitat.

Seagrass and Seagrass Beds

Convict surgeonfish are the roaming sheep of the reef but, instead of noshing on grass, they feed on algae.

Helpful Herbivores

A sunset over Boston Harbor.

Signs of a Recovering Harbor

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