What Characteristics Must Organisms In The Intertidal Zone Have?

I had to study this in biology. The 3 main problem I can remember for most intertidal organisms are temperature control, physical stress and drying out.

Since intertidal organisms are frequently exposed to both marine and land conditions their climates temperatures vary a lot. For this reason, intertidal creatures must have be resilient to temperature changes and have a variety of different biological mechanisms to deal with this, for example their enzymes may work at a wider temperature scale.

Physical stress comes from the tide and wave pressure acting upon them. Animals like mollusks have hard outter shells, and grab onto rocks to avoid being pulled away.

Lastly animals need to have mechanisms to deal with drying out when the level of water drops. Some animals have water proof membranes around their skin, or have better osmoregulation within their body systems. There are probably more adaptations, but there ya go...

The Intertidal Zone or littoral zone is the area where sea and land join together. The majority of animals of this zone are marine and are  predators.