What is the irony in the novel the old man and the sea?

in the book the marlin is being eaten by sharks until just the bones are left. At the end of the book people just think the bones must be what's left of a shark
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Andrew Ryan is man with a vision, creating an ideal and perfect utopian society. To escape the trappings of what he considers outdated moralities, he constructs his dream on the bottom of the ocean... Read More »
http://www.ehow.com/how_8518492_irony-achievement-bioshock-2.html

Irony is a concept that is difficult for many students to understand. There are three types of irony: dramatic, situational and verbal. Verbal irony is the easiest for students to understand and is... Read More »
http://www.ehow.com/info_8478064_verbal-irony-activities.html

Want to take true revenge on that maniacal Sander Cohen in BioShock? Well, getting the secret Irony achievement will certainly do the trick. Unfortunately, it isn't easy to acquire - if you complet... Read More »
http://www.wikihow.com/Unlock-the-Irony-Achievement-in-Bioshock