I can well believe that, and I imagine that it's the main reason why the OP is proposing to hire a van and move the fish and associated equipment himself, separate from the main removal van etc.
However, as I said, there are also countless specialist transport companies (aka 'couriers') who could well no what the OP wants/needs - at a price.
Kind Regards, John
Unfortunately, not countless companies. Our little Island does not have the sort of choice that you guys on the adjacent larger Island have!
We are prepared to put the work in to do it ourselves, it's just that it's a little difficult.