5 Dollars - Charles III 1st Portrait - Popoto Maui Dolphin, Silver Proof

The Māui dolphin (*Cephalorhynchus hectori maui*) is the world's smallest and rarest marine dolphin, with the population estimated at fewer than 55 adults as of recent surveys — confined almost entirely to the shallow coastal waters off the west coast of New Zealand's North Island. The subspecies has been pushed to this extreme by gill-net and trawl fishing, with bycatch mortality identified as the primary driver. "Popoto" is its Māori name.

New Zealand Post has issued conservation-themed coinage for decades, but the Māui dolphin's situation lends this particular release an uncomfortable edge: the animal depicted may not survive to see the next generation of collectors handle these coins.