Timeline question

Is it stated anywhere how much time has passed between the last film and the first scene in this one?

As the guys in the sub think the Mosasaurus would've died by the time they arrive, is it supposed to be just before the rest of the film occurs? If so, they made the Indo-Raptor very quickly. If it's a year or so earlier, and the Mosasaurus swam free at that time, why has its presence not been noted as it eats its way through the oceans?