They need a stable pH level to be able to live because if they are used to a steady pH and all of a sudden goes to acidic their body cannot withstand that transition such as humans going from hot to cold temperatures. For example, corals are sea organisms that provide homes for other sea animals that are having babies or a place to have. Coral is affected by acid in the manner of not being able to grow and limit its ability to expand and increase its population. As well, affect them before their development and before building their own homes. Some coral is able to withstand a larger pH scale but others are not and either die or become