Are there damages to the turtles if barnacles are not removed?

Barnacles are related to crabs and lobsters. They attach themselves permanently to a hard substrate. Barnacles can cover the turtle to such an extent, that they can disable the flippers and cover the eyes and nostrils to such an extent, that the turtle is unable to swim, see, smell, or even survive.

Several types of barnacles can be found on sea turtles. These barnacles can either cause minimal stress such as increase surface drag and impede the movement of the turtle, or more serious with damage to shell causing bacterial or fungal infections to enter.

It was reported that the major effects of barnacles on diamondback terrapin were the interference with nesting activity and shell erosion. In a few cases, such erosion was severe enough to cause fatal injuries to turtles.