freezing down fresh sandeel

A few mates kindly netted me some sandeels and i packaged them into 12-15 eels per pack and froze them straight away. I was told not to use them for a while and leave them in the freezer for at least a month, whats the optimum time to leave them so there at their prime? and does this apply to mackeral fillets as well?

The gemeral rule of thumb is about six weeks, but different sea conditions can change this. Sometimes fresh frozen works and other times eels that have been frozen for a year and gone a little off work, it's getting to know what ones to use thats the trick.