got these a few years ago at a good price. sealed in the freezer and sill good. they make us sick. the only thing we could figure out was every time we ate anything from the sea we both got sick. and may be they are full of microplastic.
so our solution seeing how no one in the family wants them either is bury them in the garden.
Even frozen, they are past their use by date.
Microplastic from a serving of fish is unlikely to make you sick. It is more likely that they are contaminated with a chemical.
Good price could have been due to problems in handling and storage.
Stories are told of frozen food sitting on a dock thawing in hot weather–before getting moved to the freezer. Does it get sold anyway?
Probably past. Nothing lasts forever.