skip to main content

Science Nation: Crabs Put the Pinch on Marshlands

2 minutes 34 seconds

DCMP is transitioning to player-based accessibility features, allowing for customization of captions, description, language, and playback speed. Learn more about these features and how they can be beneficial in an educational setting.

Learn More

Now Playing As: Captioned (English) (change)

Report a Problem

A quick glance at the marsh next to Saquatucket Harbor in Harwich Port, Massachusetts, reveals right away that some of the grass is missing. The cordgrass there, and all around Cape Cod, has been slowly disappearing for decades. Marine ecologist Mark Bertness of Brown University studies this critical ecosystem, which protects our coastal environment by nurturing a complex web of plants and animals, filtering nutrients, and serving as a critical storm barrier. Bertness says the marshes are being overrun by purple marsh crabs because their main predators, blue crab and finfish, are being overfished. So, the purple marsh crabs are free to gorge on healthy fields of cordgrass and once done feeding, they leave behind nothing but lumpy fields of mud.

Media Details

Runtime: 2 minutes 34 seconds

Science Nation
Episode 1
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 2
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 3
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 4
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 5
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 6
3 minutes 6 seconds
Grade Level: 9 - 12
Science Nation
Episode 7
4 minutes
Grade Level: 9 - 12
Science Nation
Episode 8
4 minutes
Grade Level: 9 - 12
Science Nation
Episode 9
4 minutes
Grade Level: 7 - 12
Science Nation
Episode 10
3 minutes 19 seconds
Grade Level: 10 - 12