Question: How did this become a problem?
Answer: Strong Urchin recruitment in 2011, Warm water conditions in 2013 known as the "Blob", Sea star wasting disease effecting 20 species of starfish, and poor kelp recruitment all combined to allow urchin populations to increase.
Question: How extensive are the urchin barrens in Monterey?
Answer: Nobody tracks a single species, but I estimate there are about 2,000 acres of urchin barrens containing about 80 million purple urchins. This is based on RCCA data and personal observations. There is an effort in this project to map urchin barrens.
Question: Won't the sea otters eat them?
Answer: No, at least not on starving urchins. Sea otters are a land animal struggling to survive in cold water and must consume 25% of its body weight in a day. Openly grazing urchins do not have gonad reserves and have little nutritional value. Sea otters eat a wide variety of foods and some specialize in eating urchins, but they are wise enough to not rely on starving urchins for food.
Question: Don't people eat them as sushi?
Answer: Uni comes from harvested red sea urchin gonads. Purple urchins are smaller and not harvested commercially. The purple urchins in the urchin barrens are openly grazing, looking for, but not finding, algae to devour. They are starving and their gonad is reduced to basically a hollowed out test. There is not a commercial market for purple urchins.
Question: Won't they just go away on their own?
Answer: Urchin barrens are an alternative stable state. unless there is some perturbation in the stable state it will remain that way for decades. Possible purturbations are: cold water, pollution, predation (Sheaphead, spiny lobsters), and disease. Disease seems the most possible when the urchins are in such close proximity. A disease was thought to have occured in Southern California in the 70s that reduced their numbers and there is evidence that urchin disease is effecting urchins again in SoCal.
Question: Can I just smash them when I dive?
Answer: No, it is illegal to smash urchins. Killing critters without a purpose is considered "wanton waste". With a fishing license you can take 35 urchins per day, but that excludes the urchins in the MPA's where the accessible urchin barrens reside. Plus, there are so many urchins that removing 35 is simply not enough. Efforts to remove urchins must be coordinated so that entire area is cleared to a low urchin density where kelp has a chance to establish. Randomly smashing them is ineffective and unlawful.
Question: Are divers removing them up north?
Answer: CFGC has changed the regulatory language to permanently increase the bag limit of purple urchins to 40 gallons of purple urchins in Sonoma and Mendocino Counties only. We are proposing a similar regulatory language change in Monterey.
Question: Will smashing them create a spawning event and make matters worse?
Answer: Maybe, but it doesn't matter. There is no peer reviewed scientific publication that proves that smashing purple urchins causes a spawning event. The urchins are starving and lack genetic material and before smashing random samples of urchins are cut opened and a GI test is performed to ensure that they are starving and lack gonad. The amount being smashed is statistically insignificant relative to the enormous amount of urchins spawning at their most effective time in spring. More likely, small mashed urchin remains are eaten by fish and other urchins.
Question: Have purple urchins been a problem in other areas and what was done?
Answer: Purple urchins have been successfully removed in Palos Verdes California. Until MPA restrictions were put in place urchins were removed in Orange County 3 days a week for 12 years by volunteer divers. On the California north coast, frustrated abalone divers are removing urchins bi-monthly at organized events.
Question: Will removing urchins bring back kelp?
Answer: In other areas where urchins were removed, giant kelp came back very quickly, within a month it was growing, and the following year it was a kelp forest again. This project will study removal to determine how this dynamic works in Monterey Bay to inform a larger removal effort.
Question: What's the hold up? When can we get started?
Answer: The California Department of Fish and Wildlife has granted Reef Check a permit to get started. Sign up on this website! We are petioning for emergency regulatory language change that will allow recreational divers to remove urchings ata site not in an MPA this sping. Sign up and we will notify you when the event is scheduled.
Please contact me to ask any other questions. There may be other people with the same question.