Clean the trash off beaches and persuade people not to litter into the water by handing out fliers or putting up posters.
nothing.
They have laws to not kill animals.
Dolphins have helped drowning people to survive.
Dolphins survive in many ways but be specific. Do you mean how they survive from prey or survive in sleep? Dolphins survive from prey by pretending they are dead, or they can swim in schools. Dolphins survive in the water by turning half there brain of when they sleep so they can still see out of one eye.
nothing
Dolphins can't survive on land.
Dolphins use echolocation to "see" around them when the water is murky. They can use it when they can't see with their eyes and also use it to locate fish and prey.
maybe because if there were other dolphins that went to their habitat then they mit not survive
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Dolphins hide from sharks and dolphins can also sense danger.
A dolphin's blowhole helps it breath while it is in the water.
fish or squid