There is a RM10 Tioman island fee, also known as "Tioman Toll" payable by all Tioman travelers before getting in the ferry to Tioman. The charge is RM20, although students pay just RM15. Note that this fee is only charged in Mersing. Travelers departing to Tioman from Tanjung Gemuk aren't charged this fee.
Separately from this Tioman Toll is the so-called Marine Park Fee. This is also known as Tioman Conservation Fee. This charge is RM 30, though the elderly, students and IKO travelers have their own respective discounts. For details, please see this link