Not just climate change, pollutants and marine traffic. It was not enough to ban hunting: there is also the culture of cetaceans and the transmission of knowledge to the younger generations
I beluga they started to decrease in Alaska for about 50 years. Once upon a time the local populations went hunting for these white cetaceans of the cold arctic waters to obtain food, but also for the skin and fat which was highly valued. Now in Kotzebue Bay, north of the Bering Strait, where the coasts of Alaska face the Russian coasts of the Siberian far east, few are left chasing the belugas at the end of spring, which also represent a cultural heritage for the Iupiaq Inuit communities. Belugas have been protected for years and hunting is allowed only to locals, but nevertheless these mammals are decreasing year by year. Scientists are looking for the reasons, which are more than one, but now they are thinking that it is something deeper, which has to do with the cetacean life system itself and their way of transmitting knowledge from one generation to the next.
The cause
Between causes of decline of belugas in many (but not all) parts of Alaska there is definitely climate change, which is affecting the Arctic more than all other areas of the world. Furthermore, the increase in naval traffic that disturbs the specimens, the decrease in prey and the chemical pollutants discharged into the sea which, through the food chain, come to contaminate the cetaceans must also be counted. But that is not enough to explain what is happening. Belugas and cetaceans in general, as happens in other animals such as chimpanzees, birds and among human beings themselves, transmit from one generation to another the lessons learned for hunting, travelling, dangers. But with the speed of change affecting their habitats, belugas are called to develop new knowledge in order to adapt.
The changes
Marine biologists have noticed this in killer whales: each group-family develops its own characteristics of communication and behaviour. And when resources are scarce, the older specimens (almost always the older females) take the lead to hunt. Probably because they remember techniques learned from previous generations. Scholars have shown that pods with the presence of orca grandmothers have a better chance of survival than those without elderly specimens. In the case of belugas, the cultural process is much faster than the development of a genetic-evolutionary adaptation, which requires many generations. A similar phenomenon has also been noticed among the belugas in the Svalbard Islands, Canada and other areas of Alaska: when the older specimens decrease, the acquired knowledge is no longer transmitted to the younger generations who, in practice, no longer know what to do and they have to learn from scratch. But for that, it takes time. And maybe belugas don’t have any.
December 9, 2022 (change December 9, 2022 | 11:27 am)
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