From salt to sea, how does life recolonize a marine basin?

For the first time in 55 years of scientific ocean drilling, researchers have recovered a complete sediment core spanning the moment the Mediterranean Sea transformed from a salt-encrusted basin back into a thriving marine ecosystem. The core, drilled during an expedition in the Aegean Sea, captures the end of the Messinian Salinity Crisis—a period when the Strait of Gibraltar closed, the Mediterranean largely dried up, and most aquatic life vanished. Until now, scientists have had only fragmentary records of how marine communities recolonised the basin when the strait reopened. This core offers the first continuous, high-resolution archive of that ecological recovery. This is fundamentally curiosity-driven research. It asks a basic question about how life rebounds after an extreme environmental shock. The findings will not directly change a technology or industry tomorrow. But understanding how marine ecosystems reassembled under past conditions—when ocean chemistry was radically different from today—provides a natural benchmark for predicting how modern seas might respond as warming and acidification make them increasingly hostile. Similar fundamental studies of past climate transitions have, over decades, underpinned the climate models now used to guide infrastructure planning, coastal defence, and fisheries management.