Kardashians -- Spoil Nautical Birthday Celebrations for Everyone ... Official Investigation Launched

Khloe Kardashian's birthday fireworks for James Harden will almost certainly change the laws in L.A. over what people can do in the middle of the night on the high seas, and heads could roll.

L.A. County Supervisor Don Knabe -- one of the most powerful politicians in California -- tells us the midnight pyrotechnic show violated every noise ordinance in the books, and he's indignant the L.A. County Sheriff's Dept. didn't shut it down.

Knabe is irate that the Sheriff and Fire Departments got a flurry of 911 calls from upset/scared/outraged residents yet did nothing, even though the Sheriff has "nice new boats" which could have reached the fireworks launch in seconds.

Khloe and company didn't need a permit for the 15-minute show, which stunned the Supervisor. He says the laws will be strengthened and any law enforcement agency that failed to react will be dealt with appropriately.