Tuna can most definitely be frozen and it is important that you follow these instructions so you do it right. First you will want to make sure that you have your tuna in a tightly sealed plastic container so no bacteria is able to grow on it while it is being stored. It might actually be a good idea to freeze two smaller containers rather than one large one so that you will be able to use the tuna salad that is thawed on within just a few days.
The second step in the storage process involves placing the lid on the container, making sure that there is at least a half-inch of space between the actual tuna and the lid of the container. This extra space will allow for the expansion which occurs during the freezing process. Another thing that you will want to do is to put special freezer tape over the lid of the container so you will be able to make sure that no air gets inside while it is being stored in the freezer.