Maui dolphins are so endangered, you could probably fit all of them in one big aquarium!
The Maui's dolphin is the world's rarest and smallest of the dolphin community. There are an estimated 55 left that are at least one year old as of 2012—a measly number that could easily deplete to zero if they aren't careful.
Thee dolphin's name comes from the Maori word for New Zealand's North Island (not the Hawaiian island), where is the only place to find them.
They generally stick close to the shoreline in groups, hanging around in 20 meter deep water.
Their numbers have dwindled thanks to set-netting and trawling, killing off an average of almost five per year—a large percentage for a species with very few numbers left. A New Zealand wildlife fund attempted to promote a fishing ban over what is believed to be the dolphin's entire range, which many in the New Zealand government were opposed to.
Instead, as of June 2014, about a quarter of the dolphin's sanctuary, 3000 square kilometers, were opened up to oil drilling. Kind of the opposite of saving the fragile animal's existence.