Yes, you can touch a starfish in water. Starfish are resilient creatures and quite tolerant of human contact. When they’re underwater, they don’t usually move away from your hand so it is safe to pick them up gently with two fingers or use a net to scoop them up. If you do choose to pick one up, make sure the environment you’re picking it out of is healthy for the species and that your hands are clean without chemicals on them which could harm the starfish if transferred from your skin or clothing onto its body. It is also important to remember that when handling a starfish their fragile spines may easily break off and cause injury so handle carefully! Once out of the water try not to keep it out too long as oxygen levels will be low outside its natural habitat and prolonged exposure can be fatal; this is why returning any creatures found in nature back into their home should always be done as soon as possible after observation has been made.