More than 2,200 years ago, a battle between the Romans and the Carthaginians took place at sea off northwestern Sicily. Rome was victorious, defeating the other fleet and ending the First Punic War.
While so much was destroyed at the time, scientists have recently discovered a shipwreck teeming with underwater life. Researchers found at least 114 animal species living on a ship’s ram from a Carthaginian vessel that was sunk in the battle.
A ram is a beak-shaped battering weapon fitted to the front of a fighting ship designed to damage an enemy’s vessel. It was usually driven into the hull of another ship in order to damage or sink it.
The ram’s discovery is an important archaeological discovery. But finding it as a host for so much fauna also provides insight for scientists learning how marine animals colonize empty sites and slowly create diverse and rich communities.
“Shipwrecks are often studied to follow colonization by marine organisms, but few studies have focused on ships that sank more than a century ago,” said last author Sandra Ricci, a senior researcher at Rome’s Istituto Centrale per il Restauro (ICR), in a statement.
“Here we study for the first time colonization of a wreck over a period of more than 2,000 years. We show that the ram has ended up hosting a community very similar to the surrounding habitat, due to ‘ecological connectivity’—free movement by species—between it and the surroundings.”
Looking for Life
The ram was recovered in 2017, located between 75 and 90 meters (about 250-300 feet) deep. It’s bronze and hollow, allowing it to accumulate sea creatures both inside and outside.
Several years later the ram was cleaned and restored by ICR researchers. All the marine animals found inside and outside the ram were collected, along with blocks of sediment and hardened materials from the same area.
Scientists have been working to compare the species found in and around the ram with those found in similar Mediterranean habitats. They reconstructed how it had likely been colonized by dispersing larvae from those habitats.
They found a complex community with 114 living invertebrate species including 58 species of mollusks, 33 species of gastropods, 25 species of bivalves, 33 species of polychaete worms, and 23 species of bryozoans.
“We deduce that the primary ‘constructors’ in this community are organisms such as polychaetes, bryozoans, and a few species of bivalves. Their tubes, valves, and colonies attach themselves directly to the wreck’s surface,” said coauthor Edoardo Casoli from Rome’s Sapienza University.
“Other species, especially bryozoans, act as ‘binders’: Their colonies form bridges between the calcareous structures produced by the constructors. Then there are ‘dwellers,’ which aren’t attached but move freely between cavities in the superstructure. What we don’t yet know exactly is the order in which these organisms colonize wrecks.”
The results were published in the journal Frontiers in Marine Science.
“Younger shipwrecks typically host a less diverse community than their environment, with mainly species with a long larval stage which can disperse far,” said corresponding author Maria Flavia Gravina of the University of Rome Tor Vergata.
“By comparison, our ram is much more representative of the natural habitat: It hosted a diverse community, including species with long and short larval stages, with sexual and asexual reproduction, and with sessile and motile adults, who live in colonies or solitary. We have thus shown that very old shipwrecks such as our ram can act as a novel kind of sampling tool for scientists, which effectively act as a ‘ecological memory’ of colonization.”
