Hey #SharksChat, I'm Marcus Drymon from University of South Alabama and I use shark muscle tissue to study what they eat...

Muscle samples give us the chance to use chemistry to study the trophic position of Gulf of Mexico sharks, information we need! #sharkschat

Based on the recent assessment, blacktip sharks are doing OK (good news!) #sharkschat

Thrilled to participate in Expedition GOM, my role was sampling muscle tissue to better understand what these majestic fish eat #sharkschat

Indeed, the stable isotopes of nitrogen, carbon and sulphur. Cool stuff! #sharkschat

Directly beneath the primary dorsal fin; sulphur gives you similar information to carbon, and adds an element for a mixing model #sharkschat

Thanks for the great questions! #sharkschat