Roman Dolphins

Study on bottlenose dolphin off Rome


Thanks to the support of Oceancare (2011-2012) and Unicredit Carta Etica (2014-2015), in 2010 Oceanomare Delphis started the project “Delfini Capitolini” with the aim of ensuring a better knowledge of the presence and ecology of bottlenose dolphins in the waters of the Roman coast(and its interactions with human activities). Aim of the study is to produce useful information for the conservation of the species in the area.

In the Mediterranean sea, the bottlenose dolphin is classified as “vulnerable” in the IUCN Red List. The species is protected by the Bern, Barcelona and Washington Conventions and by the Habitats Directive.

The study area covers an area of approximately 300 square km; it is located in the central Tyrrhenian Sea, at the mouth of the Tiber River, off the coast of Lazio, southeast of Rome.

It is delimited to the north by the oil platforms R1 and R2, to the south by the Marine Protected Area (MPA) “Secche di Tor Paterno”, and to the east by the 100 meters bathymetry.

The MPA “Secche di Tor Paterno” was established in 2000; with a surface of 13,87 sqare km it is the only Italian MPA totally off-shore. It is a Site of Community Importance of the Natura 2000 network.

The mouth of the Tiber river is a particular environment where the freshwater, which flows on the surface of the sea without mixing with the salt water, carries for hundreds of meters or even for kilometers an great amount of nutrients, essential for the activation of the marine food web.

The river also contributes significantly to the development of marine plant life and is responsible for the high productivity of the area.

The study and monitoring program, carried out since 2010, has been designed to collect useful data to: 

  • define the occurrence of bottlenose dolphin in the area;
  • study the ecology of the species (distribution, abundance, habitat use, behavior);
  • analyze population structure and dynamics
    identify the impact of the local maritime traffic on the presence, distribution, feeding, and social behavior of dolphins;
  • determine the extent of overlap between the feeding behavior of dolphins and fishing activities;
  • evaluate the extent of by-catch, if present

Observations conducted by ODO researchers revealed that bottlenose dolphins are regularly present in the area during all months of the year and interact with trawling activities.

Photo-identification data showed that 76 adult individuals frequent the area, including 3 females (identified through photographs of the genital area, the presence of an infant with fetal folds closely associated with an adult, and the behavior of supporting and carrying a dead young (documented with video) and 5 probable females (individuals consistently observed in close association with juveniles).

Thanks to citizen science, the project enjoys the collaboration of boaters and fishermen, the Coast Guard, and the technicians of the Rome refineries, who have provided real-time reports that have increased over the years, demonstrating the public’s interest in safeguarding their territory.