There is nothing much there for tourists.. the town is pretty small and like many smaller towns in Japan, many of the shops are very old.. or closed..
But for some reason, Shiogama has many sushi restaurants for a town of its size. Apparently, it has the highest "density" of sushi restaurants in the whole of Japan. The area is pretty famous for its seafood, due to a fish wholesale market at the bay.. and also for its sushi.
The sushi there is pretty good and the most famous one is from this shop called Sushi Tetsu.
Sushi Tetsu - they stamp their name on the tamago-yaki
Even the maki (rolled sushi) is very good..