Mike, you can read my report on Catalina at
www.scubaboard.com/showthread.php?s=&threadid=16181
It will give you an idea of what the area is like. I understand the Northern Islands are even better.
As to the fishing issue, I know a lot of divers here in SoCal love to spearfish and catch lobsters.
Having learned diving in the Mediterranean, this was somehow a surprise to me. Over there, spear fishing is only authorized if you're snorkeling, not scuba diving. One can argue that commercial fishing is really more to blame than the occasional diver. But, as for myself, I like to dive, like most, for the marine life. To look at it and take pictures of it, not to bring it back at home...And I'm all for whatever is done to protect it. I let the people whose living depends on fishing handle that part for me.
Restricting certain areas from fishing usually helps. Even when temporary, those measures have long term effects on the environment, where the fishing industry may be more strictly short term minded. However, putting all the blame on the fishing industry would be like accusing the farmers of being responsible for the ozone layer. Fishing, like hunting, does have some benefits and does help regulating the eco-system, as long as it's done in a responsible manner.
In short, let's hope that the fight against pollution in SoCal is not diverted. An industry or a recreational activity shouldn't be singled out and take the fall for all the others.