Each year the University of Delaware asks
for volunteers to help count horseshoe crabs in Delaware
Bay. Counting the number of things that live somewhere is
called a census. In May and June the college does a census
during the spawning season so they can estimate how many
horseshoe crabs live in the ocean near Delaware. I first
started horseshoe crab counting when I was six years old,
and this is my sixth year as a census taker.
Flat Stanley came along to help us.
To count the crabs we use a 1-meter square made of plastic
pipe. We start at one end of a beach, walk 10 meters, put
the square on the ground and count how many crabs are in the
1-meter square. We have to keep a separate count of how many
male and female crabs are in the square. We do this 100
times, which means we count over a kilometer of beach.
In the 2006 census at Pickering Beach, DE, we counted 756
total horseshoe crabs in 100 samples. This means there’s an
average of 7.56 horseshoe crabs per sample. If every meter
of the one kilometer beach held the same average of crabs,
that would mean that that there were 7,560 horseshoe crabs
on the beach.
For more information on horseshoe crabs, visit the Horseshoe
Crab Census site at http://www.ocean.udel.edu/mas/bhall/hsccensus/
LTC C.J. Wallington
Advanced Technologies, PEO EIS
[submitted by Tory Wallington, fifth grade, Riverside
Elementary School, Alexandria, VA]