Every year, like most of the animals, salmon migrate from one place to another. Now, researchers have made a study about it. They found out that salmon migration is because of environmental problems.
The salmon migration is because each salmon is getting signals off of the same environmental cues. Since the signals they get are all the same and at the same time, they move and migrate also at the same time, said Andrew Berdahl, an SFI Omidyar Fellow. Salmon migration could be triggered because of a certain change in tide or water temperature or the patterns of the moon, according to Phys.org. The climate change is now affecting the time and the signals that the salmon are getting for them to migrate into places, he added.
There are also other scientists that suggested that natural tidal waves and moon phases may have also cause salmon migration. For 20 years, researchers have been observing the salmon migration up in Alaska's Hansen Creek. The temperature and levels of the said creek are very steady so some of the reason might not apply to the creek. After seeing the pulsed movements, Berdahl and his co-researchers are thinking that there really might be other reasons for the cue of the migration. "Maybe they're cueing off each other," he guessed.
Social clues might be one of the reasons, argued Berdahl and his colleagues in a new paper published in the journal "Animal Behaviour". They have built the same model wherein an individual will lead the rest of the group. If one fish will migrate, chances are the others will follow soon, UPI reported. The model has proven that it might have been a cascade effect, which created the pulse-like pattern that happened in Hansen Creek and elsewhere. Salmons are not copying the others but are simply being smart because moving in a group is better than living alone, especially if an animal is a vulnerable prey.
"If you want to know how migratory animals are going to respond to this change, you have to pay attention to social interactions," Berdahl explained. "Which is what we think determines the fine-scale movement decisions -- or you're going to miss an important part of the picture," Berdahl added.
