Eric Sedletzky
Contributor
The thing is they are not invasive, they are native, they are just completely out of balance at the moment. This is what the scientific community is struggling with. They don’t want them completely gone like lion fish or something that doesn’t belong there at all. Purples belong there at a population rate of about two per square meter. However, with no natural predators around two per square meters goes unchecked and becomes 200 per square meter, so the scientific community need to decide if they want purples or kelp because right now you can’t have both.
The giant sunflower stars were the natural predator for purple sea urchins. However about 13 years ago there was a mass die off of sunflower stars and other stars. They Identified the disease as sea star wasting disease but they are still mystifies as to what caused it. They figure most likely pollution but they don’t know the exact mechanism.
So the purple urchin population was able to explode unchecked and as a result has eaten everything in their path. 95% of the kelp forests were lost all up and down the coast. Diving became a thing just to look at barrens, a purple carpet devoid of anything growing, no fish, no kelp, nothing but bare rock and purps.
I like to dive regularly and it was hard to swim over them seeing what they are doing to get to deeper water so I could hunt, which there really wasn’t much left to hunt with no kelp. So I decided to do something about it and went to work clearing urchins since that was about the only reason left to go diving locally. I picked a cove to concentrate all my efforts on and started from the beach and worked out. It’s important to clear an area completely to give kelp spores a place to start and form a hold fast. We have a pretty sizable group now that are very dedicated. They share the same motivations as I do. It’s become something of an obsession.
