Biggest Marine Migration of Sardines Found Pointless With No Impact to Evolution While Most of Them Die in the Process

The migration of animals is among the most activities that could change the fate of a species. Mass migrations should be conducted by a lot of animals because of food requirements, the temperature of the climate, or even mating opportunities. However, a recent study suggests that the larger a migration occurs, the greater it brings unusual impacts. In some cases, animals migrate for no qualified reason that will benefit the environment nor themselves.

Sardine Migration

Among marine life, sardines are active fish that are fond of migrating from different parts of the ocean. Millions of sardines in the seas of South Africa are known to participate in large migrations every single year. Numerous oceanic predators also migrate in flocks to have a better source of food for each of their groups. Even fowls migrate, and they are observed by both experts and enthusiasts for a celebration. Some organizations set up annual events just to observe the beauty and rarity of immigrating birds.

To analyze the migration deeper, experts chose the large group of sardines as they can exist and travel between different oceanic regions. Based on the recent study conducted, there is an unusual reason why sardines migrate in a unique way compared to fish species and other animals. The reason they found out serves as a threat rather than a benefit for the sardines.

Africa is surrounded by two of the greatest oceanic regions on the planet. The currents present on the continent are made up of the Antarctic ocean's fresh water and the Indian Ocean's tropical water. Because of the fusion of water currents originating from two distinct regions of Earth, temperature gaps can be recorded just a few kilometers off the shore of South Africa.

Worst Migration in Marine Evolution

The difference between the temperature gap does not affect sardines much, and in fact, they could swim and migrate between both of the water currents whenever they choose to. But despite this ability, there have been clues suggesting that the sardines may have been divided into different groups that have evolved with respect to each of the oceanic water conditions long before time. This could be the reason why we first thought that the same group of sardines could travel in distinct water bodies.

Flinders University expert and author of the study Luciano Behegeray said in an IFLScience report that there is a possibility where the genetic studies on the sardine species missed and failed to determine the distinct groups present on each of the two great oceans intersecting on South Africa. The expert added that their recent study was the first and most comprehensive study on identifying the thousands of sardine genomes to distinguish the difference of each migrating group. The results of their examination showed two distinct sardine populations, but both of which are still correlated with each other.

Their study, however, did not focus on what happens between these species. But they were able to find out that due to the warming of Atlantic waters, the group present on it has no chance but to migrate to the Indian Ocean during its upwelling. But when the upwelling ends, the migrated sardines are eventually trapped in the foreign habitat, making their groups vulnerable to the natural extremities and intense prediction. Because of this, sardines are the first species known to conduct the worst and most useless migration of all time. The study was published in the journal Science Advances, titled "The sardine run in southeastern Africa is a mass migration into an ecological trap."

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