Scientists from the Tursiops Association detect 48 sperm whales north of Menorca

The Tursiops Association's Moby Mummy campaign recorded eleven encounters with sperm whales during a two-week research expedition. The discovery was made during the organization's field campaign, conducted between July 17th and 30th.

Scientists from the Tursiops Association have detected 48 sperm whales in waters north of Menorca during a two-week research campaign, sailing approximately 1,100 nautical miles. They found that around 20 percent of the animals observed were calves.

The findings were made during the association's research expedition, carried out from July 17th to 30th as part of its Moby Mummy project, which focuses on identifying and protecting a sperm whale nursery area north of Menorca.

Researchers searched for and located sperm whales, photographed their flukes and dorsal fins for individual identification, recorded the codas and clicks they produce using acoustic equipment, and captured aerial imagery to assess their body condition, identify possible pregnancies, and obtain morphometric measurements.

During the two weeks at sea aboard a sailing vessel, scientists recorded eleven encounters with sperm whales, two acoustic detections and nine visual and acoustic encounters. The two acoustic detections, made using hydrophones, involved one group of five animals and another of two.

In addition, researchers visually identified three solitary males and six groups comprising a total of 38 sperm whales, including nine calves. The largest group consisted of seven whales, three of which were calves. "The fact that more than 20 percent of the animals found in groups are calves is excellent news," said Txema Brotons, Scientific Director of the Tursiops Association.

Brotons emphasized the significance of the findings, noting that "the waters north of Menorca are full of animals, full of groups, and full of calves," which demonstrates "the strength and stability of the sperm whale population in this area."

Successive editions of the Moby Mummy campaign have confirmed the existence of a sperm whale nursery area in Menorca's waters. The site lies in a region with relatively low shipping activity and away from the main routes used by large commercial vessels, making it a key habitat for the conservation of the species.

Tursiops, which has been studying the Mediterranean sperm whale population (Physeter macrocephalus) since 2003, has asked Spain's Ministry for the Ecological Transition to establish a Marine Protected Area (MPA) north of Menorca to safeguard what it considers the principal breeding and nursery ground for sperm whales in the western Mediterranean and to reduce the impacts of human activities.

According to Brotons, Spanish Prime Minister Pedro Sánchez endorsed the creation of the protected area last summer as one of five new marine protected areas announced during the United Nations Ocean Conference (UNOC3) in Nice.

Now that the proposed protected area has been delineated, researchers are focusing on gathering as much information as possible about this essential and stable nursery habitat while exploring the most effective management measures.

"We will focus our efforts on identifying the pressures and threats affecting the species so that, once the protected area is officially designated, we can present a management plan that is truly effective in reducing the most significant impacts," Brotons said.

In addition to photo-identification, researchers studied the whales' acoustic behaviour "to distinguish differences in codas, identify cultural variations, and compare them with populations elsewhere." They also collected samples for environmental DNA (eDNA) analysis in collaboration with the University of Valencia.

Although sperm whales were the primary focus of the expedition, the team also recorded sightings of other marine wildlife during the two-week voyage. They observed five bottlenose dolphins (Tursiops truncatus), three groups of approximately 70 Risso's dolphins (Grampus griseus), and six groups of striped dolphins (Stenella coeruleoalba) totaling around 104 individuals. Researchers also sighted 21 loggerhead sea turtles (Caretta caretta).

The campaign was supported by Menorca Preservation, the Menorca Biosphere Reserve Agency, Menorca Lines and Marina Port Mahón.