Finding Diseased Sea Stars in Tide Pools

Sea star missing legs. Photo from UCSC

When exploring tide pools anywhere between Alaska and California, watch out.  You might find a sea star (starfish) missing legs or looking really gross.

What is wrong with them?  

Up and down the Pacific west coast, sea stars have a disease called Sea Star Wasting Disease.  It can kill a group of sea stars within just 24 hours or a few days.

Scientists at the University of California, Santa Cruz, along with

A leather star (Dermasterias imbricata) just beginning to show signs of the disease, seen on San Juan Island in October 2013; Photo: Keith Rootsaert

other researchers remain unsure why this disease has hit the west coast sea star population so rapidly.  There is a bacterium (vibrio) that scientists have identified through pathology.  And warmer ocean waters are also suspected as a cause.

With an adult, you can participate in observing the sea star wasting symptoms.  Visit www.seastarwasting.org.

It Lives to Eat Other Starfish

If you were a five legged (or ray) starfish just hanging around the undersea rocks and you saw this 13-legged starfish coming your way, you better move fast.  Why? Because it's probably coming to get you.

With nicknames like the 13-Arm Hammerlock, or Cannibal Sun Star, this rare but aggressive  Dawson's Sun Star  (solaster dawsoni) even looks menacing, or maybe more like a creepy character from Pirates of the Caribbean.  And it also dines on other starfishes.

The above photo was recently taken off the shores of Big Sur, along the central coast of California, during a Monterey Bay Marine Sanctuary field project.

The Dawson's Sun Star has no natural enemies--except itself--henceforth, that cannibal nickname.

A Dawson's Sun Star devouring another starfish.

All photos from NOAA/Monterey Bay Marine Sanctuary