As sea levels rise – due to climate change and other natural factors – the “salt line,” a natural barrier where inland water meets the ocean’s salty water, is shifting.

Buried at Sea Records of fresh water being found offshore go as far back as the 1800s. Fishers off Florida have occasionally reported “boils” of water on the ocean's surface, which they assume ...

In winter, Florida manatees migrate from the sea to the warmer freshwater springs inland, such as Crystal River in Florida on The Americas Season 1, Episode 6. Photo: BBC Studios ...

“Ghost forest” in Nags Head Woods, North Carolina, where saltwater intrusion puts low-lying freshwater ecosystems at risk. As sea levels rise, the ecosystems nearest to the water are most at risk.

Visitors on the morning July 24, when a heat wave warning was issued, play in the water at Nonjitmul, a natural beach created ...

Jay Exum and Mike Cliburn, board members of the Friends of the Wekiva River, examine the fresh water of the spring on Dec. 11, at Rock Springs in Apopka, Fla.

Over-pumping and even over-loving the springs are partly to blame. According to the GeoPlan Center’s Florida 2070 report, Florida’s population is expected to grow by 12.2 million by 2070 ...

Listen • 4:10 Zack Wittman for NPR Jay Exum and Mike Cliburn, board members of the Friends of the Wekiva River, examine the fresh water of the spring on Dec. 11, at Rock Springs in Apopka, Fla.