I check and it appears that whales don't gain anything from the barnacles that hitch a free ride. I suppose it is like us in an airplane, though we are not completely harmless as we add a great deal of noise, commotion and weight.
http://www.learner.org/jnorth/tm/gwhale/Hitchhikers.html
In the New Yorker, there is an article on the slums surrounding the airport in Mumbai. It is titled Opening Night, The Scene from the Airport Slums and is by Katherine Boo. (I love that last name.) She is contrasting the slums and the "beautiful" people preparing for the opening of the film "Slumdog Millionaire." Those attending come to the hotels surrounding the airport to be "manicured, exfoliated and blown out."
I find this paragraph particularly sobering as to how we are all now tied.
"The banks in America went in a loss, then the big people went in a loss, then the scrap market in the slum areas came down, too," was how Anna, who read the Tamil-language newspapers, had explained the crisis to the residents. A kilo of empty water bottles, once worth twenty-five rupees, was now worth ten. This was how the crisis was understood."