Thousands Of Dead Jellyfish On San Francisco Beach

More than 10,000 jellyfish, each about the size of a dinner plate, washed up on Ocean Beach, in San Francisco, last Friday, November 12.

According to experts, they are probably moon jellies, which have a pinkish hue and leave intricate, flowerlike imprints in the sand when they dry up.

Unlike the Portuguese man o’ war, whose stings can be fatal to humans, moon jellyfish are so mild the toxins rarely penetrate human skin.

Apparently this is nothing to be alarmed about. Jellyfish tend to congregate in groups, and tides, the wind, ocean swells and currents can combine to send the groups ashore. Jellyfish have been washing ashore around San Francisco Bay for at least 500 million years, said Mike McGill, a marine biologist at the Aquarium of the Bay.

And the California coast is home to about 20 species of jellyfish, all of which are thriving.

Check out this amazing sight here:

Creative Commons - joanna8555


Beth H.
beth Hall6 years ago

They are such unique creatures but this is the circle of life.

Martha Eberle
Martha Eberle7 years ago

Patricia A., you're right on it. If humans are involved in any way, ..... Bye bye. How the stupidest species got to be at the top of the brain chain, .... ?!

Barbara Erdman
Barbara Erdman7 years ago


Patricia A.
Patricia A7 years ago

No doubt us humans had a hand in this too as we are destroying our whole planet. Bye Bye!

Jennifer Martin
Jennifer M7 years ago

Seems strange to me. That's a lot of dead jellies...

Amber M.
Amber Beasley7 years ago


Steven J.
Steven L Jones7 years ago

Google Jellyfish plague. Then this will be seen in context.

Gita Sasi Dharan
Gita Sasi Dharan7 years ago

Poor animals! What caused their death?

Jeffrey M.
Jeffrey M7 years ago

Since my degree is in Mathematics, I must defer to McGill on this matter.

I like poll questions that simply test my understanding. They're easy. :-)

Elle E.
elle g7 years ago

In Oz we have the Box Jellyfish, so called because it has 4 distinct sides. This pale blue, transparent, and extremely poisonous marine stinger frequents Australia's northern oceans all year round but it's presence peaks during the rainy season. They swim into the shore in calm waters when the tide is rising, gathering at the mouths of rivers, estuaries and creeks following rain. They have up to 15 tentacles on each corner which can be 3 meters in length. They can have up to 5,000 nematocysts (stinging cells).

You don't go swimming in the ocean during these peak times as they are deadly. Wet suits help limit contact with tentacles as does swimming or surfing in panty-hose. You have virtually no chance of surviving the venomous sting because the pain is so excruciating and overwhelming that you would most likely go into shock and drown. They cause more deaths than snakes, sharks and salt water crocodiles.

Domestic vinegars should be poured liberally over the tentacles to inactivate stinging cells as soon as possible. The tentacles may then be removed. It's not highly unusual to see someone screaming on the beach, being doused with vinegar while waiting for the ambulance. Artificial respiration and cardiac massage may be required. Never use methylated spirit or alcohol.

The Irukandji, another deadly Australian jellyfish are only 2.5 centimeters in diameter and much harder to see.

Sometimes both critters are just refereed to as Stingers.