The two beluga or white whale (Delphinapterus leucas) specimens that live in the l’Oceanogràfic aquarium located in Valencia, Spain, emit different sounds which are being studied by the personnel of the centre. According to the researchers, the analysis and study of these sounds “is impossible to be conducted in their natural environment, but here at the aquarium is very easy thanks to audiograms”.
The research department of the l’Oceanogràfic has been investigating the bio-acoustic function of the belugas since their arrival in 2003 from an aquarium located in Mar del Plata, Argentina. “In order to maintain animals in captivity, we are obliged to have an associated research project that justifies that measure. In the case of the white whales, we are investigating the varied repertory of sounds these cetaceans have, which makes them being known as the ‘canaries of the sea’”, said Antonio Estéban, responsible for the department that is conducting the study about the belugas’ language.
The fact that these marine mammals are emitting sounds is a proof of their good health condition and their adaption to their new habitat in the aquarium of the l’Oceanogràfic. Estéban explained that “when this species feel threatened their acoustic activity reduces dramatically. When Yulka and Kairo arrived to the l’Oceanogràfic they didn’t emit any sound. After three weeks, they started emitting sounds again and nowadays they communicate as they used to do in the aquarium of Mar del Plata, where they didn’t live in captivity.
It was important for the study to check if the belugas had changed their behaviour after being relocated. For that reason, the researches took two aspects into account, “on the one hand, we paid attention to the number of sounds they emitted per hour and, on the other hand, the type of sounds they emitted, because they have a large repertory of sounds”.
The sounds these cetaceans emit have two main functions: the first one is for social communication, which is indispensable to keep the group’s cohesion and to establish hierarchies in the group and to individualize family units. The second function is echolocation, because these cetaceans use the sounds as a sonar transmitter to find their preys. “Depending on the sound, we observe the behaviour attached to it”, said Estéban. This study can contribute to the lack of knowledge about the biology of this species. The results of this project will be used in future researches on belugas in their natural environment because “these studies are impossible to be carried out in their natural environment, but here at the aquarium it is very easy because we can use audiograms”, added Estéban.
In 2007 it was held at the “Ciudad de las Artes y las Ciencias” in Valencia an international workshop about belugas in natural and artificial environments. During the event, scientists agreed that “there is little information about the Delphinapterus Leucas to assure their conservation”, said Estéban, and he added that “we concluded that if we make the necessary researches before they become an endangered species, like it happened with the Iberian liynx, we would be able to have the necessary information to protect them”. This was the first time that research teams that had been working in the study of the white whales in artificial and natural environments exchanged information about the results of their researches.
The Delphinapterus leucas dolphins, commonly called belugas or white whales, live in the Arctic area, near the North Pole where there is a huge acoustic contamination. The aquarium of the l’Oceanogràfic imitates the natural environment of walrus and belugas with rocks and ice blocks. Besides, these animals that are very social ones are provided with the necessary stimulus to feel comfortable in the artificial habitat, sharing with seals or having toys that stimulate their instincts. “The belugas have the capability to notice when there are children looking at them and they love interacting with kids”, said Pilar Tormo, responsible for the press department.
The l’Oceanogràfic has developed a series of breeding and research programs. A seal, a flamingo, a shark, two bottlenose dolphins and two Humboldt penguins were born in the facilities of the aquarium since its opening in 2003.
The major achievement in term of breeding programs was achieved the 2nd of November, 2006, when the belugas had their first baby, which was the first specimen born in captivity in Europe. The offspring only lived 25 days, which was unfortunate but expected by the scientists due to the captivity conditions. However, the birth of this cetacean in captivity was very important for the research project aimed at the conservation of the white whales, because it provided information about their biology and the experience for future births in captivity. “It is normal that the first newborn in captivity die, but the fact that the female beluga got pregnant in captivity shows that the conditions of the aquarium are good for their reproduction”, concluded the chief director of the research.