How this ancient dolphin population thrives in one of Italy’s most polluted cities

Where the heel meets the boot of the Italian peninsula, along the Ionian Sea, lies the ancient city of Taranto.

Founded by the Spartans in 706 B.C., the city is older than Rome, and according to Greek mythology, its origins involve nymphs, wars, sons of gods, and dolphins—lots of them.

“The dolphin becomes a kind of totemic animal of the city, as if it were the protector animal. Not just symbolic but really protector of the city, linked to the foundation myth,” says Giovanni Pietro Marinò, archeologist from MArTA, Taranto’s archeological museum.

Dolphins are as plentiful in the city’s history as they are in its waters. But despite being the symbol of the city, it wasn’t until the early 2000s when marine biologist Roberto Carlucci from the University of Bari started to ask questions about how many exist, where they mate and feed, and how they survived in a city historically dominated by a polluting industries.

The city remains visibly marked by its recent industrial past—its gargantuan structures looming over the skyline. For years, residents wouldn’t leave their homes on windy days to avoid air pollution blown into the city. Yet the region boasts unique, thriving marine life. 

“It’s like a puzzle that gets richer and richer as the pieces increase,” says Carlucci.  

An underwater buffet

Dolphins often appear in Greek and Roman mythology as benevolent sea creatures, protectors of sailors, and are connected to the god Apollo. By the 3rd century B.C., Taranto was wealthy and powerful enough to mint its own coins. It chose to forge Taras, son of the sea god Poseidon, riding a dolphin on the coins’ side, to identify the currency as coming from Taranto.

On good days, one can still see dolphins from old Taranto’s seaside promenade, coming very close to the city out of curiosity or chasing food.

A silver coin dating back to 300 B.C. depicts a man riding a dolphin. Dolphins often appear in Greek myths and have been a popular symbol of Taranto since its founding.

Photograph by DeAgostini, Getty Images

Recent studies have shown, through genetic sequencing, that the striped dolphins of the gulf have unique genetic features not found in other parts of the Mediterranean. This suggests that the dolphins seen today might be descendants of the ones the Ancient Greeks saw.    

“These dolphins have Taranto written in their DNA,”http://www.nationalgeographic.com/” says Cristiana De Leonardis, a marine biologist with the Jonian Dolphin Conservation.    

After more than a decade of surveying parts of the Gulf of Taranto, researchers at the conservation organization identified six cetacean species: spinners—which are also the largest population estimated at around 20,000 individuals—bottlenose and common dolphins, the Risso’s dolphin, and the rare Cuvier’s beaked whale. Sperm whales use the area as a nursery ground and researchers have also occasionally spotted fin whales.

(Five ways orcas are surprising scientists.)

Since monitoring started 15 years ago, the dolphin population has remained stable, and the key to their survival might lie hidden thousands of feet below the sea’s surface. 

A few miles off the coast of Taranto, between Puglia and Calabria, a submarine canyon called the Taranto Valley reaches 6,500 feet at its lowest point. The canyon is an active habitat for cephalopods, which sperm whales eat. Its steep slopes also vertically mix warm waters near the surface with deeper cold waters rich in nutrients, boosting the production of phytoplankton at the base of the food chain.          

In a well-balanced ecosystem, phytoplankton sustain a wide range of sea creatures like shrimps, snails, and jellyfish, which feeds the fish that dolphins rely on for food. Because scientists only began monitoring Taranto’s dolphin population recently, it’s unclear how humans have challenged their survival over the centuries the two species have lived side-by-side. But scientists think the canyon’s unique geography supplies a steady source of food that helps the dolphin population adapt to other stressors like pollution or boat strikes.

Over half of the Mediterranean’s dolphins and whales are threatened with extinction, making the gulf of this industrial city a surprising marine haven.

Taranto turns to its past      

The coastal Italian city wants to ensure its waters remain a sanctuary for its long residing dolphins.

Off the city’s coast, dolphins contend with several growing threats: boating, noise pollution, fishing, and rising sea temperatures. The Italian navy has its largest base there, occupying miles of waterfront. It’s the site of a NATO command center, and the city’s commercial harbor is expanding. The first Italian offshore wind plant was inaugurated in 2022, and along the northern shores of the city, energy company Eni has a large oil refinery plant.

Underwater noise pollution from these activities poses a risk to marine mammals like dolphins, studies show. Dolphins use sound to communicate with each other, navigate their surroundings, and find food, and the underwater noise generated by marine traffic and industry disrupts these essential behaviors.

Less clear is how air pollution from Europe’s largest steel plant, a public-private enterprise referred to as ILVA, may impact dolphins. Carlucci believes “it’s almost impossible that the pollution generated along the coast doesn’t have an impact” on the marine environment and its creatures. But determining a direct correlation between factories pollution and specific impacts requires more research.    

Taranto’s steel production peaked in the 1970s, and industrial byproducts have allegedly been linked to a number of health concerns. Now, city officials want to install a marine protected area to create a healthy environment for both people and dolphins.

Photograph by Donato Fasano, Getty Images

This steel plant marked the city’s environmental landscape for decades. Built in the 60s, production peaked at the turn of the 1970s and 1980s when it employed more than 40,000 people, roughly 16 percent of Taranto’s population at the time, and produced more than 17 million tons of steel annually. The plant now produces around three million tons a year, a reduction partially driven by lawsuits alleging a link between hazardous emissions and deadly health conditions like cancer.

Now, Taranto seeks a greener future for both humans and dolphins.

“This city suffered the mistakes that many parts of Italy did. We cut our connections with the sea to build industries,” says Rinaldo Melucci, the mayor of Taranto. He wants to rebuild those connections and transition the city from its industrial past to a more sustainable future.

To preserve this unique population, local politicians are now working with scientists to establish a marine protected area (MPA) in part of the gulf. An MPA would boost preservation efforts, increase resources for research, and set rules aimed at limiting noise pollution and ship traffic.

(Inside the ambitious push to protect a third of the world’s ocean.)

The MPA is still pending approval from Italy’s Ministry of Environment, with no clear deadline. Nevertheless, Melucci, the city’s mayor, is pushing ahead and says the city will start setting up the local offices that might one day monitor the MPA. Notably, Italy is among the European countries with the lowest number of MPA, according to the European Environmental Agency, despite being one with the most miles of coastline. 

Marine biologist Carlucci worries that an increasingly active harbor will harm the ancient Taranto population before marine protections are established: “My biggest fear is that we are going to be too late when we finally establish one.”

Transitioning from Taranto, the city of ILVA, to restoring the city’s environment has been a slow, challenging process. The old town, which was off limits until a few decades ago, is being restored and reopened. Cruise ships now dock at Taranto harbor, and the city is attracting international sea sports events.

Says De Leonardis, “I want Taranto to be the city of dolphins, once again”.

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