Posted by green trees on January 13, 2003 at 16:45:48:
In Reply to: Boring Subject "Sea Urchin" posted by Steve on January 13, 2003 at 13:22:18:
like many things in nature it's not black and white.
I belive it is well established that the purple urchins put pressure on the giant kelp.
They don't climb the stips, rather they directly eat the holdfast which will release the plant,
and it will die.
Santa Monica BayKeepers performs some studies in addition to replanting the giant kelp. They relocate the purple urchins,
(because smashing them will just cause them to reproduce more).
The red urchins are kept in check by the sushi market, the natural preditors of the purple urchin have been reduced causing their numbers to multiply.
The preditor's included otters, sheephead, and large lobster.
as stated aboube, heat does hurt the kelp. as does setiment.
if the combination of pollution, urchins, heat reduces the forest beyond the point of no return, then the forest is lost.
GT