Lagrangian coherence and source of water of Loop Current Frontal Eddies in the Gulf of Mexico

•Loop Current Frontal Eddies are formed by the convergence of Gulf of Mexico water.•Once formed, Loop Current Frontal Eddies can remain Lagrangian coherent for weeks.•Loop Current Frontal Eddies are Lagrangian coherent from the surface down to 560 m.•Large Loop Current Frontal Eddies modify the flow and the transport of oil and tracers.