I just noticed this claim for sale on Trade Me:
There’s pictures of a dredge which suggests you can dredge but I believe the local iwi has banned suction dredging on this claim.
There’s also this questions and answers post:
Apologies I can’t answer a question here because it seems to be against Trade Me rules.
Which seems like BS. I think someone might be trying to sell the claim under false pretenses, so beware any potential buyers.