Every day at dawn, bird-watchers board boats at small villages near the coast of northeastern Italy to explore a natural wonder—the Po Delta Biosphere Reserve, a UNESCO-designated site, where the iconic 400-mile Po River meets the Adriatic Sea.

In the shallow waters and knotty reed thickets, visitors look for purple herons and pink flamingos, just two of the 360 bird species that flock to the country’s only delta and largest wetland. They also catch another sight—local women wading in the water, pulling up rascas (a type of rake with a net) which they use to catch clams.