[Legbreaker]

It's doubtful any significant numbers of reinforcements would be available. The best way to utilise the otherwise useless naval personnel is to retrain them for supporting roles that keep them (relatively) out of harms way and free up others for the front lines.
However, how many reactor techs, communications experts and the like are there really going to be given the destruction of their ships around them while at sea? Those sailors who do survive being sunk aren't likely to be very great in number, and many of them are quite likely to be low ranking general hands rather than high value skilled specialists.
And there's likely to be even fewer submarine crew surviving - just look at the Last Sub modules to see just how few could be found to crew the Los Angeles, and they had almost an entire continent to draw from.

The handful of specialists would certainly be horded and transferred immediately to ships such as the John Hancock or Tarawa to make up losses there. The ratings are just more mouths to feed which can be used anywhere unskilled labour or combat replacements are needed.

Now if you work with my premise of the Tarawa being sunk during the 2000 offensive, you've suddenly got a reasonable number of naval crew clogging the beaches (numbers depending on how the Tarawa was lost and how many got ashore). The Marine commanders will see these men in two ways - more mouths to feed and protect, or useful replacements, probably both. With little to no chance of returning the sailors to a ship, thee would be quickly scooped up and put to work, some receiving a crash course in infantry tactics, others continuing in similar roles to those they had afloat (logisitics, mechanics, heavy weapons, communications).

All of them should know at least the basics of weapons handling and many should also know a bit about small unit tactics (one of the roles of the Australian navy is border protection which includes boarding ships, searching small islands, etc. They might even be better suited to urban environments than regular infantry due to their extensive experience of tight confines).