For the life of me I can't find Oysters in brine anywhere (Im in Kent, UK)
I can get hold of mussells in glass jars stored in salt water (Nickname "The poor mans oyster).
As far as I can see Mussells are practically the same as oysters. Do they have the same nutritional content (Or there abouts?) Zinc, copper etc
Don't know how accurate this is but: http://www.jpshellfish.com/nutrition_shellfish.php
For the same calories, oysters have like 100x as much Zinc, Copper. 3x Selenium, Magnesium, Calcium etc