skip to main content

The Remarkable Horseshoe Crab: Part 3 (Why Count the Crabs?)

3 minutes

(Describer) Under a round logo of a wave, title: Ocean Today.

(Describer) Ripples of ocean water reflect golden light.

(Describer) The moon shines above.

(Describer) A few people wearing headlamps walk on a beach, one carrying a frame.

(woman) We really do have a crab line tonight. This is so exciting.

(Describer) Dozens of horseshoe crabs are in the mud. One woman writes on a clipboard. Maggie Pletta:

Okay. Twelve and three.

(woman) Here in the Delaware Bay, in Delaware and New Jersey, we complete spotting surveys every year from May into June. It's so important to do these surveys to know how many horseshoe crabs we have to manage them for biomedicine, the eggs for the migratory birds, as well as watermen who collect them.

(Describer) Light clouds pass over the moon.

We go during full and new moons, when you have the highest tides. With volunteers, we take measurements every 10 meters down the beach. We count in a one meter by one meter quadrat how many male and female horseshoe crabs we have. Four females and eleven males. Okay, okay.

(Describer) The quadrat is the frame. Title: Citizen scientists have conducted standardized surveys since 1999.

(Pletta) That data is collected from Cape Henlopen in Southern Delaware all the way up to Woodland Beach and across the New Jersey side as well. Zero, zero. Zeroes are data.

(Pletta) All that data is put together and used to determine our spotting population of horseshoe crabs in the Delaware Bay.

(Describer) Titles: Find out how you can join the survey at de.gov/dnerrhscsurvey and HorseshoeCrabSurvey.com. Logos are shown for the Smithsonian and NOAA Accessibility provided by the US Department of Education.

Accessibility provided by the U.S. Department of Education.

Transcript Options


Now Playing As: Captioned (English) (change)

Report a Problem

During horseshoe crab spawning season, volunteers are dispatched along the Mid-Atlantic coast to help scientists track their populations. Learn how citizen scientists track the data to help preserve the horseshoe crab. Part of "The Remarkable Horseshoe Crab" series.

Media Details

Runtime: 3 minutes

The Remarkable Horseshoe Crab
Episode 1
2 minutes
Grade Level: 7 - 12
The Remarkable Horseshoe Crab
Episode 2
2 minutes
Grade Level: 7 - 12
The Remarkable Horseshoe Crab
Episode 3
3 minutes
Grade Level: 7 - 12
The Remarkable Horseshoe Crab
Episode 4
3 minutes
Grade Level: 7 - 12
The Remarkable Horseshoe Crab
Episode 5
3 minutes
Grade Level: 7 - 12