Thanks to social media, canned sardines are a scarcity on the supermarket shelf. If you’ve noticed empty shelves where canned sardines used to sit at your local grocery store, you aren’t imagining things. Supermarkets across the country are facing a noticeable shortage of the popular staple, leaving shoppers scrambling to find their favorite brands. The missing tins are the result Thanks to social media, canned sardines are a scarcity on the supermarket shelf. If you’ve noticed empty shelves where canned sardines used to sit at your local grocery store, you aren’t imagining things. Supermarkets across the country are facing a noticeable shortage of the popular staple, leaving shoppers scrambling to find their favorite brands. The missing tins are the result of a sudden spike in popularity colliding with severe environmental problems out at sea. For generations, canned sardines were seen as a cheap, humble pantry item.…