sea anemones

Playing Environmental Jenga


Jenga is a game . . . where players take turns removing one block at a time from a tower constructed of 54 blocks. Each block removed is then balanced on top of the tower, creating a progressively taller but less stable structure. The name jenga is derived from a Swahili word meaning "build".   From Wikipedia


Here on the north coast of California, August usually sees all the coves filled with floating masses of Bull Kelp, Nereocystis luetkeana, which is an annual, and food for at least 50 organisms. It covers rocks and washes ashore on the beaches, attracting birds to the flies it draws. Down the coast in Monterey, it's where the sea otters nap. 

This summer the coves look more like this.
photo by Ron LeValley
Bull kelp has been disappearing, presumably eaten by an abundance of spiny sea urchins. Sea urchins are preyed upon by starfish, properly call sea stars, but there has been a die-off of sea stars from what has become known as "Starfish wasting syndrome."

"As voracious predators on the ocean floor, sea stars are ‘keystone’ species that have a large role in maintaining diversity in their ecosystem."

In a study done at the Cornell University , the disease was found to be a parvovirus commonly found in invertebrates.  

"There are 10 million viruses in a drop of seawater, so discovering the virus associated with a marine disease can be like looking for a needle in a haystack. . .Not only is this an important discovery of a virus involved in a mass mortality of marine invertebrates, but this is also the first virus described in a sea star.”

“It’s the experiment of the century for marine ecologists,” said Harvell (of Cornell.) “It is happening at such a large scale to the most important predators of the tidal and sub-tidal zones. Their disappearance is an experiment in ecological upheaval the likes of which we’ve never seen.”

This may be one block too many pulled from the stack.