One of the perils of preservation is the addition of sodium to foods.. I understand how pork must be brined before smoking etc. but Shrimp?
USDA reports that 3 ounces of regular cooked shrimp contains 805 mg of sodium!
According to Cooking Light online, Shrimp run from 97 to 730mg of sodium per 4 oz when tested. Fresh, never frozen was the best with the easy to peel varieties coming in on the high end.