In case you're wondering the context of this video: this was uploaded by a commercial kina (common sea urchin; Evechinus chloroticus) harvester off the coast of Aotearoa. Here's his YouTube channel. Kina populations have exploded recently due to decrease in predator numbers, and consequently they're overgrazing kelp ecosystems and creating urchin barrens. That's why there are so many in this video. So this guy is helping get numbers down to a sustainable level.
(Also for clarification: the urchins are not invasive. They belong in this ecosystem; there's just too many of them to be sustainable)
Also, the ones he's harvesting are probably going to be food. Kina is a Maori delicacy and even some fish and chip shops serve it. It's not strange to come across a pile of several dozen empty shells on the beach, you just crack them open and slorp like an oyster.
I mean, I'd check that your local stuff is safe to eat first but if you want to help the environment and get a free lunch out of it, it's worth a shot
