Until the beginning of this century, it was estimated that the population of the North Pacific fin whale (Balaenoptera physalus), the second largest cetacean on the planet, has lost 70 percent of its effective population. However, a genetic study carried out by the Advanced Genomics Unit (UGA-Langebio) of Cinvestav and the University of California at Los Angeles (UCLA), among other institutions, determined that the damage caused by industrial whaling in the bag -well hundreds of years, though. bigger.
Among the main participants of the study, published in the journal Communication in Natureinclude Andrés Moreno Estrada and Sergio Nigenda Morales, researcher and then postdoctoral fellow at UGA-Langebio, respectively, who together with experts from UCLA sequenced the genomes of 50 specimens of whales from the northeast Pacific and the Gulf of California.
According to Sergio Nigenda Morales, the study used samples stolen over decades from specimens in two regions (Pacific and Gulf), where they were able to completely sequence the genome of marine mammals and establish that the fin whale population loss in the Northeast. Pacific it is 99 percent of effective individuals (portion that reproduces), so it suggests continuing and increasing all possible conservation efforts to protect the species.
Genomic research also serves to confirm that the Gulf of California population is sparsely populated and has a relatively different genome from the rest of the Pacific; In other words, there is little migration between the two groups.
“This gives us the understanding that the population of the Gulf of California is almost isolated, there is very little flow of specimens entering or leaving to and from the Pacific. It has been proven that there are very few individuals with mixed genetic backgrounds among those from other regions, what is surprising is that they are genetically different when the distance is short and accessible to whales from the North Pacific,” commented Nigenda Morales, who is currently a research professor at California State University, San Marcos (CSUSM).
By strengthening this genetic information about the population of fin whales in the Gulf of California, they will help to identify these individuals (only about 114 individuals) as very vulnerable, because if any disruption of the environment or presence of a new pathogen, the effects. can be severe, with small population sizes and limited adaptive potential, a consequence of low genetic diversity.
“We found in several analyses, especially heterozygosity, where it is possible to identify genomic sites with variants, that individuals from the Gulf show less genetic diversity compared to samples from of whales in the Pacific, where we proved that the entry. of specimens off the coast of Mexico is about one individual every three generations (approximately 75 years),” explained the researcher.
The importance of these studies, according to members of the research team, is to inform the importance of protecting this species of whales, because they are bioindicators of the health of marine ecosystems, but to know also possible entry routes. , also called, the Sea of Cortez to avoid the collision of cargo ships that would further reduce their number.
According to Nigenda Morales, the tissues used for genetic sequencing were obtained over several decades by experts from the National Office of Oceanic and Atmospheric Administration of the United States and the Autonomous University of Baja California Sur, while the Sequencing was obtained at UCLA, and is both verified and checked by the UGA-Langebio infrastructure.
By confirming in this research that there are genetic differences between the populations of the Gulf of California and the Pacific Northwest, the future intention of the scientists involved in this project is to study whether there are physical or physiological adaptations or diversity that eventually results. of a new species of mammal in the Gulf of California.