text:  The land loss is down to a few factors, oil and gas exploration, sea levels rising, and the flood controls and levees that have shackled the Mississippi River to stop it overflowing. But now, the state is trying to fix this, starting work on the largest ecosystem restoration project in US history. It's being paid for by nearly $3 billion in settlement money from BP's Deepwater Horizon disaster, which 13 years later is still the world's worst oil spill.