Increased sightings of pods of dolphins in several locations around the Maltese islands could be the result of a decrease in underwater noise, as COVID-19 has ground many typical activities to a halt.
The reduction in underwater noise could account for increased sightings of cetaceans in bays around Malta, marine biologist Alan Deidun told Times of Malta.
"While it's not possible to deduce the exact reason we've seen sightings of dolphins so close to the shore, some theories are more credible than others," Deidun said.
"Typically cetaceans stay away from the coast because they are very sensitive to underwater noise. An absence of that might signal there is less chance of getting hit by a boat, which happens to cetaceans frequently."
Dolphins pods were spotted at the Marsamxett port and close to Fort Tigne on Sunday afternoon.
Underwater noise, generated by marine vessels, underwater excavations and construction or pile driving as well as acoustic surveys, can be detrimental to the mammals, causing disturbances which could alter their migratory pathways, Deidun says.
The dolphins could also be motivated by their bellies, as they were spotted in areas where pelagic fish (like mackerel or tuna), which the animals feast on, are known to reside. According to Deidun, the pursuit of prey could also be a strong motivator to venture closer to the coast.
"The dolphins were spotted in a number of bays where certain large schools of fish are known to be, so they might have ventured closer to hunt. It's significant they were seen close to fish farm locations," Deidun says.
Another reason the pod might be sticking to shallow waters could be due to an injury in the family. Deidun posits that the highly social and bonded pods would strive to protect a wounded family member, and the shallow pools would provide an easier location to do so.
Only eight different species of cetaceans have ever been spotted in Maltese waters, half of which are dolphins.
Recent reports indicate that the number of bottlenose dolphins estimated to live in and around Maltese waters ranges between 79 and 224.