The remains of nearly 200 historic ships are slowly decaying in the shallow waters of the Potomac River in Maryland, about 64 kilometers (40 miles) south of Washington DC. Now, it seems, these ships are moving. 

Known as the Mallows Bay “Ghost Fleet”, the collection of wrecks includes sunken Civil War vessels and more than 100 scuttled World War I wooden steam ships. Now officially recognized for its historic value, the wetlands area hosting this ship graveyard is also of high ecological value. But after centuries of integration, it’s impossible to delineate the site’s natural attractions from those of human interest.

According to NOAA's National Marine Sanctuaries, the structures provided by the ship and dock remains have become key features of the diverse marine landscape, creating habitats for populations of fish, rare birds, and other species. Yet, like all ecosystems, the ghost fleet is in flux. New research, presented last week at the American Geophysical Union’s 2018 Annual Meeting, suggests that most of the ships are slowly shifting eastwards and that some have moved as much as 32 kilometers (20 miles) since they were abandoned.

These insights are not yet published in a peer-reviewed journal, and may never be. But this is not down to any fault in the integrity of the investigation. Rather, it is likely because the ship mapping project was conducted by a class of fifth-grade students from the nearby J.C. Parks Elementary School. (Side note, the pinnacle of my fifth-grade academic achievement was building a miniature suspension bridge out of popsicle sticks, so kids are definitely getting more ambitious.)

As reported by Live Science, the class was inspired to study the Ghost Fleet after a field trip to Mallows Bay last year. To determine whether or not the ships were moving, they compared numerous maps of the wreck sites and consulted Google Earth.

In their presentation at the meeting, the students reported that the forces driving the drift include storms, floods, and erosion. They also determined that the parts of the boats embedded in mud have remained the most intact, whereas the parts exposed to the currents and above water are more deteriorated.

The students concluded that the fleet’s movement could have a significant impact on the estuarine ecosystem and that future investigations should utilize remotely operated underwater vehicles to more precisely document changes in position.