The Obama administration is proposing a ban on swimming with dolphins in Hawaii, a move that would crush vacation dreams of many tourists but would allow the playful nocturnal species to finally get some sleep.
The National Marine Fisheries Service says spinner dolphins are being deprived of rest during the day and becoming stressed out.
The dolphins, which get their name from their habit of leaping in the air and spinning around, rest half their brains and keep the other half awake so that they can surface and breathe. As a result, they can look awake and active even when asleep.
The dolphins hunt at night and gather in shallow bays during the day for protection from predators, making them a popular attraction for tourists. Dozens of companies operate daily dolphin tours on Hawaiian islands.
The proposed rule would cover waters out to nearly four nautical kilometers, which is where 98 percent of Hawaii's spinner dolphins rest during the day.
The federal agency plans to hold public meetings on the regulations next month and expects to make a final decision next year.
The U.S. government has previously passed specific regulations barring people from approaching within 100 yards of humpback whales in Hawaii and Alaska, and killer whales in Puget Sound. This would be the first rule addressing swimming with spinner dolphins.