Dolphins may have been attracted to port because of less maritime traffic, biologist says

A reduction in maritime traffic could be one of the reasons bottlenosed dolphins were spotted swimming in Marsamxett Harbour, Marine biologist Alan Deidun told MaltaToday.

A video shot on Saturday showed dolphins swimming just metres away from the shore, with the aquatic mammals taking advantage of the significant drop in activity due to the COVID-19 lockdown.

“It is difficult to give a definitive answer; but a reduction in maritime traffic, could be a reason for the sighting due to less reactional vessels, water taxis, etc – which are are a common occurrence at this time of the year,” Deidun said.

Bottlenose dolphins are a regular presence in Maltese waters, with their population in 2014 estimated to range from 79 to 224, with the lower figure considered more realistic.

Deidun explained that dolphins are incredibly sensitive to noise; due to the auditory cortex of the brain being highly developed. Because of this, dolphins are capable of detecting noise and traffic from a great distance, he said.

A dolphin auditory nerve is about twice the diameter of the human eighth nerve, leading to more rapid sound processing for dolphins – this meant that the pod may have detected less noise and thus made their way to the harbour.

Deidun said another viable reason for the dolphin’s presence was that they were hunting. “Because a pod was witnessed and not a singular dolphin– and they were observed in an area close to where fish farms are located; it is very possible they were attracted because of prey.”

But it was not unheard of for dolphins to come close to the coast at this time of year. However, Deidun highlighted that it looked as though the pod had swum into the harbour by design; as if “they wanted to be there” which could be attributed to less activity out at sea.

READ MORE: Bottlenose dolphins spotted in Marsamxett amid COVID-19 calm