We found another fin whale in the Velebit Channel
During a successful search for a fin whale in the Velebit Channel in August 2020, researchers from the Croatian Natural History Museum and the Blue World Institute photographed an adult individual on 17 August in front of Starigrad-Paklenica.
Since reports of sightings in the southern part of the Velebit Channel, Ražanac, Vinjerac and Novsko ždrilo, continued in September, the researchers returned to the field with the aim of recording the fin whale from the air with a drone in order to analyse its size and health condition, take a skin biopsy for DNA analysis and make additional photographs for identification.
They found the fin whale already on Saturday, 5 September, at the very entrance to Novsko ždrilo.
They followed the whale for about two hours inside the strait itself, when it swam to the new Maslenica Bridge and returned to the Velebit Channel.
After leaving the strait, the whale swam in the direction of Vinjerac, and since its dives lasted up to 38 minutes, the researchers gave up further tracking and filming.
However, by reviewing the photographs taken, they determined that it was not the same animal that had stayed in the area in mid-August, but another whale!
“After I took the first series of photographs, I went to check their quality and at first glance I noticed that the fins of the previously photographed whale and this whale were different. Namely, the whale that colleagues photographed in August had a large and visible notch in the fin itself, while this whale does not have such a notch. The fins also differ in shape,” says researcher Mr. Jure Miočić-Stošić.
“Almost unbelievable, but only half an hour after this discovery, we received a phone report from citizens who had observed another whale in the Vir Sea!”
These photographs therefore confirmed the information we had obtained by collecting citizens’ observations, namely that at least two fin whales are present in the northern Adriatic.
During the morning of 6 September, the researchers went out to sea again and found the same fin whale somewhat north of Novsko ždrilo itself.
“Besides the fact that its dives were shorter, this time the fin whale was interested in our vessel. On several occasions, it swam alongside our boat for 4-5 minutes just one metre below the surface. During one approach, it turned on its side and its almost white belly was clearly visible,” says Grgur Pleslić, Director of the Scientific Programme of the Blue World Institute.
“We saw a larger number of parasitic crustaceans, Penella sp., on the whale’s body, but we estimate that the infestation was not so severe as to represent a health problem for the animal,” Pleslić continues.
Assoc. Prof. Draško Holcer, PhD, senior curator of the Croatian Natural History Museum, performed a skin biopsy of the fin whale.
“On several occasions, the whale swam very slowly alongside our vessel. Such a situation is favourable for taking a biopsy because it allows you to hit the animal precisely without risking possible injury or a miss. During one such surfacing next to the vessel, I managed to fire a biopsy dart with a crossbow and take a small piece of skin for DNA analysis,” says Dr. Holcer.
“As far as I know, this is the first successful biopsy of a fin whale in the Adriatic. About ten years ago, however, I managed to take a biopsy from a humpback whale that stayed in the Bay of Piran. At that time, it helped us determine the sex of the animal. We will immediately send this sample to colleagues in the Netherlands who are currently conducting population genetic research on fin whales of the Mediterranean and Atlantic, and I hope that the results will arrive as soon as possible,” Dr. Holcer continues.
The researchers also recorded incredible drone footage of the fin whale, which you can watch on the YouTube channel.
Source: Blue World Institute