Based on it’s location in reference to the other islands, it most likely represents Kahoolawe, an island used as target practice by he navy, and is now uninhabited because it’s full of unexploded ordinance, or Molokai, an island forbidden to all but native Hawaiians. Either way…
minor corection, Niihau is the island forbidden to all but native hawains, and it’s nowhere near right geographically, that does look like Molokai though, and molokai is actually known for being a secluded leper colony until 1969