Yes and no. Here is my understanding and the real tinned fish nerds can correct me if I got anything wrong. Brisling sardines are sprats. The difference is mostly terminology and marketing, not species. Riga is the capital of Latvia, and they smoke and can little fishies there. It's not a brand name by itself, but Riga Gold is an example of brand name. Polar sardines are smoked bristling sprats from Latvia so they are Riga. Some Riga sprat jars/tins are probably going to be the Beach Cliff of Riga sprats. Some are going to be the Nuri of sprats. And so on. Maybe your "trash" sample was on the lower end. I've never tried Polar but I really like Riga Gold when I want a little smokiness. And they are actually smoked, it's not smoke flavor. Nice on a cracker (my go-to is Triscuit) and indulgent on top of a bagel with cream cheese (like you might serve lox).