So, I read most of the Seasteading book by Quirk and Friedman, and I was talking about it with my friend the other day. After describing how Takahashi wants to raise whale sharks for meat, my friend jokingly suggested using whale sharks as transportation and it occurred to me that since people are already making aquatic robots to move seaweed up and down between nutrient-rich but deep water and sunny surface water (Marine BioEnergy company), you could maybe just make a harness for a mature whale shark and get the whale shark to do that for you. As in, the whale shark would have a harness and the harness would have a net behind it with a tiny kelp forest growing on it.

I highly doubt that this would ever work -- it probably would hurt the whale shark if the tiny kelp farm were much bigger than some fraction of the whale shark's normal biomass -- but I thought it might make you guys laugh!