Science-backed management including the size minimums, male-only, closed months, and closed refuge areas works for a lot of fisheries insomuch as there is adequate respect and abidance, and effective enforcement.
But Kona should make at least a half dozen busy dive zones strictly and officially no-take (including no aquarists)
Seen local lobster freedivers at night in heavy windward surf conditions with no direct exit from the water, swimming a kilometer back to a tiny keyhole in the lava cliffs where they know how to narrowly avoid getting smashed into lobster food. One guy's bag was full, the other's was empty. It's not Florida or San Diego
Maybe buy from the locals? Same for tuna & mahi. Small craft & big catch is their trade
Haole reef spearing/taking is a joke. Spend $2000++ on spearo schwag to go kill parrotfish?
That could buy a lot of proper offshore fish. But the spearo shops will appreciate your business. Reefs worldwide got decimated in the 70's and 80's by SCUBA spearos, many have never completely recovered.
If you see a white dude selling reef fish out of a pickup truck, take a pic and report him to DLNR.