National Fisherman: Purple urchin invasion leads to a low harvest, high prices for West Coast urchins
Too many purple sea urchins and not enough bull kelp continues to stymie California’s red urchin dive industry. Since the one-two punch of El Niño and the warm-water blob in 2016, bull kelp beds have declined by 93 percent from previous years, according to a study by the California Fish and Game Commission.
Kelp is the prime forage of urchins, and the more plentiful the kelp, the fatter they fill with prime uni. The kelp shortage has confined divers to deeper waters and concentrated their efforts in small areas where kelp beds remain.