I freedive the Pacific coast on a weekly basis year-round. The little purples are actually tastier than the commercially harvested reds to me, but it's a lot less meat for just as much work. I don't see them really making this work commercially, especially as much as the states (especially California) limit commercial urchin permits.
Thing is, the environment will sort itself out. Two years ago the urchin blight was hitting SoCal extremely hard. This year isn't so bad, a lot of places have kelp coming back extremely thick, and the purples aren't creating any kind of apocalypse. While it's true that there aren't as many sea otters as there were in yesteryear there are plenty of reef fish that eat the urchins. Sheephead are very numerous and they love crunching those guys - in fact every time I gut one it's packed full of purple urchin debris. In five years I'm sure there'll be an imbalance with too many sheephead, and we'll have some other article to read and worry about.
Thing is, the environment will sort itself out. Two years ago the urchin blight was hitting SoCal extremely hard. This year isn't so bad, a lot of places have kelp coming back extremely thick, and the purples aren't creating any kind of apocalypse. While it's true that there aren't as many sea otters as there were in yesteryear there are plenty of reef fish that eat the urchins. Sheephead are very numerous and they love crunching those guys - in fact every time I gut one it's packed full of purple urchin debris. In five years I'm sure there'll be an imbalance with too many sheephead, and we'll have some other article to read and worry about.