You may want to do a it more research on the EO position.
This position came about as a result of court orders related to the major cruise lines being prosecuted for illegal dumping at sea.
As part fo their probation, the lines were required by the US Government to place EOs on all their ships to monitor and report any problems.
The probationery period for most of the lines is either ended or nearly over. Several have already changed this position to an OSHA type job, with very little to no environmental responsibility.
The remaining lines are expected to follow this scheme as their probationery periods lapse.