What is sargassum?
Sargassum is a seaweed that consists of several species
of brown algae, many of which are free-floating masses.
Sargassum is also called gulfweed or sea holly, because
it has many branched stems and hollow, berry-like floats.
The hollow floats aid the plant in staying near the surface,
which is necessary for photosynthesis, the process it uses
to make food using energy from the sun.
There are approximately 150 species of sargassum found throughout
the world. However, two main species of free-floating sargassum
are found in the Atlantic Ocean; Sargassum natans and S.
fluitans. These accumulate in large masses in an area of
the Atlantic Ocean known as the Sargasso Sea.
This sea is a huge mass of floating sargassum off the southeastern
coast of the United States. It is located near Bermuda,
and its elliptical shape covers approximately a two-million-square-mile
area, a result of a ring of currents that enclose a large
Because of the Earth’s rotation, the eddy circulates
clockwise. This rotation keeps the sargassum from dispersing
into other parts of the ocean. The Sargasso Sea receives
little wind or rain, making it ideal for the seaweed to
Without the weed, this area of ocean, currently located
in the heart of the Bermuda Triangle, would be a desert.
There are few nutrients available here, and sargassum provides
a variety of sea life with habitat and food.
One species that uses the sargassum is the loggerhead sea
turtle. Loggerheads spend the first few years of life hiding
in the sargassum weed. Other animals, such as the sargassum
fish (Histrio histrio), actually disguise themselves among
the fronds of the weed to ambush prey.
In ancient times, sailors believed the huge masses of seaweed
would trap their ships, dooming them to sail forever in
the Sargasso Sea. However, there is actually not enough
seaweed to entangle even a small boat, much less a large
ancient sailing vessel.