GRADO, Italy, June 6 (UPI) -- Italian archaeologists say evidence from a sunken Roman ship suggests fish could have been kept alive in on-board tanks as they traded around the Mediterranean.
Due to a lack of refrigeration, historians have long assumed Roman ships catching fish could only deliver them locally or short distances away before the fish rotted.
However, a new report published in the International Journal of Nautical Archaeology concludes Roman fishing ships may have used a pumping system to supply oxygenated water to an on-board fish tank, PhysOrg.com reported Monday.
The report details a wrecked fishing ship discovered in 1986 off the shore of Italy and raised in 1999.
The find that has intrigued archaeologists was a 4-foot lead pipe at the stern of the ship that went into a hole in the hull, which they believe could have been connected to a hand-operated piston to pump seawater aboard.
Archaeologists say they have seen such Roman technology before but never on a ship.
Carlo Beltrame, a marine archaeologist from Ca' Foscari University, says he believes the ship could have held a tank with about 4 cubic yards of water and a pump would have been able to draw and replace the water every 16 minutes, keeping it well oxygenated for fish transport.
This could mean Romans were transporting and marketing fish beyond their local markets far earlier than previously thought, researchers said.