I also hope you don't intend to communicate anything that requires security or privacy because, assuming you mean HAM bands in HF, then you can't encrypt anything.
The problem with using RFC1149 is rounding up and training enough seabirds—pigeons won't fly that far over water. Albatrosses would be ideal, but there might not be enough of them available.
Hmm. Can we instead attach mesh repeater units to the albatrosses, and hope that enough of them take up optimum spacing for long-distance transmission? Or perhaps it would be better to just string a line of buoys across the Bering Strait once Russia stops being cantakerous. Then all we have to do is find a way to connect up Australia and a few assorted islands here and there.
Whales would allow for the greatest throughput, and are technically not fish, so "swimming carrier" works. Plus, another good reason to lean on the few nations that still allow whaling to stop: "Don't kill those, you'll break the Internet!!1!"
The problem with the RFC will be equalling the tongue-in-cheek silliness of 1149 and its extensions. I expect there to be a large section on "encapsulation concerns" (in other words, waterproofing).