image: This team of experts has been able to observe how the fin whale or common rorqual (Balaenoptera physalus), the largest cetacean in the world after the blue whale, has increased its population on the Catalonian coast over recent years. view more
Credit: EDMAKTUB Association
Climate change has also brought important transformations to the animal world. This has been made clear by studies carried out since 2011 by the EDMAKTUB Association (an NGO), on which the UEx professor Daniel Patón has collaborated.
This team of experts has been able to observe how the fin whale or common rorqual (Balaenoptera physalus), the largest cetacean in the world after the blue whale, has increased its population on the Catalonian coast over recent years.
Indeed, according to the annual sightings report compiled by EDMAKTUB, in 2017 alone over 300 whales were spotted, if we add together those recorded by the scientific team (102 animals) and the notifications by the network of fishermen and mariners collaborating in the project (a total of 155 reports with over 200 whales observed). This increase is principally because they have found in these waters a major concentration of food. Further, by using drones it has been possible to see how they filter-feed, swallowing the mass of copepods and expelling the water like a colander or sieve.
In fact, and from the perspective of a scientist, Professor Daniel Patón, of the Department of Plant Biology, Ecology and Earth Sciences at the UEx, explains that the rise in temperature and radiation is making the levels of chlorophyll in the seas go up.
"This, combined with the nutrients brought by the rivers and agricultural phosphates, is prompting an increase in the phytoplankton, and therefore of the zooplankton (krill and marine copepods), which is the principal source of food of this cetacean and is what makes them concentrate in these zones", according to Patón.
Specifically, the conclusions point to this increase in zooplankton as the cause of the rise in the whale populations, and these "are the great carbon sinks of the seas". In other words, according to this UEx professor, the whales are helping us to reverse the damage of global warming.
UEx contribution
For this marine biology investigation, the major contribution of the University of Extremadura has been the development of a geographical information system using a large neural network. "This is a computer model which allows the different variables which we have seen exert an influence, such as the chlorophyll, temperature, salinity and bathymetry, to be collated. These data let us understand and learn why one of the largest animals on the planet behaves in a specific way". Bringing all these variables together, it is possible to discover the whale behaviour and plot maps of the western Mediterranean. For this project, the researchers have used open-source software tools (R and QGIS) running in Linux environments.
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Reference:
Eduard Degollada, Beatriu Tort, Natalia Amigó, Cristina Martín, Daniel Patón. "A GIS Variability Model of Distribution of Fin Whales (Balaenoptera physalus L.) in Catalonian Coasts (NE Spain)". (2019) Cetaceans: Evolution, Behavior and Conservation. Nova Science Publishers, NY, USA. ISBN: 978-1-53614-998-2