This appears to be a relatively scientific institution and yet they don't use the internationally recognized unit of measurement the American football field. I have no idea how big this island is now.

It's a little cryptic, but I believe this passage "slightly longer than the Polarstern with its 118 metres and about twice as wide"

tells us it's the size of two Polarsterns laid side by side.

I still don't know what that is in terms of football fields, I assume you mean United States and not Canada, but maybe someone else can help out as I've gone as far as I can.