Bottlenose dolphins usually live in small to medium-sized groups in coastal and open-sea waters, but every once in a while, a dolphin might leave its pod behind, flock to coastal areas and approach human settlements. While this is a relatively rare occurrence, cases of dolphins entering coastal or urban areas are well-documented.
When a bottlenose dolphin nicknamed Mimmo was first spotted in the lagoon of Venice last summer, local researchers jumped into action. The team has now published a Frontiers in Ethology article in which they describe their monitoring activities and the dolphin's movements over several months, while also assessing management scenarios.
"We present the case of one of the most charismatic animals in one of the most iconic cities: a solitary dolphin in Venice," said senior author Dr Guido Pietroluongo, a conservation veterinary pathologist at the Department of Comparative Biomedicine and Food Science at the University of Padova. "Our observations document this animal's remarkable adaptation to an unusual context and highlight the need to manage human behavior to ensure its welfare."
The Dolphin of Venice
Two dolphin species, common dolphins and bottlenose dolphins, used to be abundant throughout the Adriatic Sea, including in the Venetian Lagoon. However, common dolphins virtually disappeared prior to the 1970s due to human impact. Bottlenose dolphins, which are more adaptable and resilient than common dolphins, still occur in the Adriatic Sea, but have been avoiding lagoon waters in recent decades.
Monitoring of the solitary bottlenose dolphin started as soon as it was first sighted in the Venetian Lagoon in June 2025. Scientists observed it from boats every week after, with support from authorities and citizens. Over a few months, the dolphin moved from the southern end of the lagoon towards Venice at the northern end of the lagoon, where it is still present.
"Observing bottlenose dolphins in urban areas is not particularly surprising, as they are extremely adaptable and opportunistic marine mammals," said Pietroluongo. Dolphins have historically dwelt in the area and are adapted to living there. "Mimmo appears healthy and is regularly observed feeding on mullets. Since his arrival in the lagoon, any behavior displayed has been typical of the species."
More worrying than the presence of the dolphin in the lagoon is its stay in the San Marco Basin, right in front of San Marco Square, the city's busiest and most popular tourist area. Staying this close to a hotspot of human activity comes with several risks the dolphin would be facing to a lesser extent in the open seas, for instance harm caused by boat propellers. Yet, in open waters dolphins would also encounter significant anthropogenic threats – primarily from fisheries – the researchers pointed out.
People management
In Venice, the greatest danger the dolphin faces comes from humans acting inappropriately towards a wild animal, particularly through irresponsible driving of boats. Measures like controlling boat speed and close approaches are necessary. "This situation is primarily about managing human behavior rather than managing the dolphin," Dr Giovanni Bearzi, the first author of the study who has been studying Adriatic dolphins for four decades, pointed out. "Recognizing the priority of safeguarding a protected species, treating it as a wild animal, and behaving in an informed, aware, and responsible way is key in wildlife management," noted Bearzi. Conservation action should be guided by experts, not sensationalist narratives, the team said.
Effective measures to safeguard both the dolphin and people include a ban on harmful interactions and strictly enforcing existing regulations – under which any disturbance of a wild, protected animal is legally prohibited. This includes attempts to touch or feed the dolphin. Such measures are vital as early attempts to drive the dolphin back into the open sea using acoustic deterrents proved unsuccessful and aren't advisable. Capturing the dolphin to displace it, on the other hand, would be bad practice which harbors more risks than opportunities.
"What is truly unusual is not the dolphin's presence, but the persistent difficulty humans have in respecting such animals today," Bearzi concluded. "We need to appreciate the opportunities to coexist with and enjoy wildlife. Historical and contemporary documentation clearly shows that dolphins have accompanied human maritime activities for millennia, yet we still struggle to coexist with them appropriately."
