From Bulbapedia, the community-driven Pokémon encyclopedia.
Pinkan Island (Japanese: ピンカン島 Pinkan Island) is a natural wildlife preserve in the Orange Archipelago.
Its name comes from a special fruit that grows on the island which turns Pokémon a pinkish color. These pink Pokémon are highly sought after by poachers, so people are not allowed on this island, and anyone caught on it is immediately confronted by Officer Jenny. Pinkan Island is surrounded by giant whirlpools, and sheer cliffs that reach high up are the only way on the island.
Pinkan Island is a Pokémon Preserve, and if any Pokémon see a human (other than Officer Jenny), they won't be afraid to attack. There are just a handful of buildings on the island that the people who help Officer Jenny stay in.
Its name is a portmanteau of "pink" and 柑 kan (citrus).
Places of Interest
Stands for the "Pokémon Reserve Preserve," it's where Officer Jenny stays. It's also where she takes anyone found entering the island illegally. There is a pot with a small Pinkan Berry tree growing by the doorway, as well as a automatic buzzer that goes off anytime someone steps foot on the island.
Pokémon Found on Pinkan Island
A pink Rhyhorn eating a Pinkan Berry