So it is Marriott's fault that people did not use their brains given the location of the hotel? Got it. Vacation means leaving the brain at home. That sign has a picture of a stingray, a jellyfish, a crocodile, and some other animal. Honestly, just seeing the pictures of the stingray and jellyfish is enough to warn you to be careful about going into the water or being on the beach. There are also two phone numbers listed with one of them being 911, which should alert you that it is a sign with some safety warning. Having google translate or some other translate app on your phone is a good idea if you are going somewhere, and you do not know the local language.
At a minimum, everyone who travels should do an online search about the risk of wildlife in the area they are traveling to. If you go to Alaska, even just Anchorage, do not be surprised if you see a grizzly bear or Alaskan moose, and they are not the type of wildlife you should provoke. The hotel can hang up as many signs as possible, and someone will find a way to ignore them and blame the hotel for their failure to take some personal responsibility for their own safety. Parents have the responsibility to make sure their children understand what safety risks are involved at the hotel or resort of their stay.