Aotearoa / New Zealand

As the other commentor said, these are elsewhere known as abalone, a large shellfish.

This is a pretty poor article because it explains nothing.

NZ has carefully managed fisheries to keep stocks sustainable as recreational fishing is very popular. There are minimum sizes they must be (the article says 159 were under this limit). It's also illegal to (SCUBA) dive for them, you have to collect near land where you can get to without diving gear. This article says the poachers were divers.

There are also daily limits per person. These vary by region because of differences in the stock, but the limits are generally 5-10 per person per day. These two people had nearly 500.

But none of the above matters. The pāua are so plentiful where they were collecting because they were collecting in a marine reserve. In that marine reserve it's illegal to fish or collect any shelfish, it's a protected area.