Since the official opening of Pier 53 as a passive park along the Delaware River in 2014, neighbors have found it to be a beautiful oasis of calm at the edge of a bustling city. But much of what makes this site so distinctive is mostly invisible.

From 1870 to the 1920s, the site was a noisy, busy immigration port, dominated by railroad tracks and warehouses with hundreds of thousands of immigrants. Then it became a disembarkation port for World War 1 soldiers, then a mercantile pier, and then, in the 1960s, it became abandoned and quiet. And forgotten.

Into this new wilderness arrived new life. Fish started appearing that hadn't been seen in decades. Rodents appeared: squirrels, and beavers, and even a groundhog. Two species of snakes were discovered to have taken up residence. Northern map turtles were found hanging out on the ruined pilings. Migrating birds showed up: hawks and eagles and egrets. And bees.

Bees make their homes in non-urban areas as well as in formerly urban and abandoned areas. Pier 53 fits that category. Where did the bees originally come from, and how had they evolved to fit into a changed habitat? Matthew Donahue, a scientist at the Department of Ecology and Evolutionary Biology at the University of Connecticut wanted to find out.