Sharks are famous meat eaters known primarily for it. Though it seems that in 2007 the body of a young bonnethead shark appeared to have some sea-grass found in his stomach. They usually digest  shrimp,small fish, and crabs and reside near to the shore and hunts in shallow water. A close relative of the hammerhead which is suspected to use microbes to digest the grass though it seems the hammer head their cousin wont be joining them for a while.   One adventurous student decided to do a experiment and collected three different bonnethead sharks put them in salt water, where he feed them 90% eelgrass and 10% squid three times a day for three weeks. In which they all ended up growing weight which proved the theory that it eats grass,with the collection of their waste (poop) it shows that they use at least 50% of the sea-grass.