Similar to how children learn, often unconsciously, to mimic the adults around them, a small, silvery ocean fish employs this tactic when teaching the next generation to find a suitable place to reproduce.
Scientists have named the strategy “go with the older fish,” and it describes a key part of the Pacific herring lifecycle that has been recognized for years by indigenous peoples, but hasn’t factored into management of the species.
As juveniles, herring join large schools offshore to mingle, eat and grow until it’s time to reproduce. Then, younger, smaller herring follow the older, more experienced fish back to specific beaches to spawn. It appears none of the fish are aware of this learning process; rather, the memory of where to go is imprinted unconsciously into their brains.
Herring migration isn’t random, and this could also explain why herring have been missing for years from some beaches, even in the few cases where the overall population numbers are adequate. If older fish that spawned at a specific beach are wiped out, there are no fish to lead the next generation to use that particular site.
Continue reading at University of Washington.
Image via Flickr.