https://www.forbes.com/sites/michaelmars...our-fault/
EXCERPT: ... The results have been published in Nature Ecology & Evolution.
[...] Atlantic salmon are evolving rapidly, and the result is they are not growing as large as they used to. The effect has been traced to a single gene. Atlantic salmon (Salmo salar) hatch in rivers in Europe, where they spend their first few years before heading out to sea. Once they reach maturity, they return to their home river to breed.
[...] When to spawn is a trade-off: a salmon that waits longer will grow larger and probably have more offspring, but it also risks dying before it can spawn at all. Primmer's team has found that the salmon are spending less time at sea growing, and instead heading back to their rivers to spawn sooner.
It is not clear why the salmon are evolving to be smaller at maturity. It could be that they are being affected by climate change in some way, or that fishing fleets have targeted the larger individuals, or something else entirely.
It would be misleading to say that the salmon's evolution is a good or bad thing. On the one hand, it suggests that they are adapting to the pressure they are experiencing, whatever it is, which seems encouraging. But it also makes clear that they are under some sort of pressure, and since we do not know what it is, we do not know how much they can endure.
According to the International Union for Conservation of Nature, Atlantic salmon are "least concern", meaning they are not at imminent risk of extinction. However, the species has not been assessed since 1996, so a second look might well revise that finding. Certainly, some of the local populations have declined steeply in recent decades....
MORE: https://www.forbes.com/sites/michaelmars...our-fault/
EXCERPT: ... The results have been published in Nature Ecology & Evolution.
[...] Atlantic salmon are evolving rapidly, and the result is they are not growing as large as they used to. The effect has been traced to a single gene. Atlantic salmon (Salmo salar) hatch in rivers in Europe, where they spend their first few years before heading out to sea. Once they reach maturity, they return to their home river to breed.
[...] When to spawn is a trade-off: a salmon that waits longer will grow larger and probably have more offspring, but it also risks dying before it can spawn at all. Primmer's team has found that the salmon are spending less time at sea growing, and instead heading back to their rivers to spawn sooner.
It is not clear why the salmon are evolving to be smaller at maturity. It could be that they are being affected by climate change in some way, or that fishing fleets have targeted the larger individuals, or something else entirely.
It would be misleading to say that the salmon's evolution is a good or bad thing. On the one hand, it suggests that they are adapting to the pressure they are experiencing, whatever it is, which seems encouraging. But it also makes clear that they are under some sort of pressure, and since we do not know what it is, we do not know how much they can endure.
According to the International Union for Conservation of Nature, Atlantic salmon are "least concern", meaning they are not at imminent risk of extinction. However, the species has not been assessed since 1996, so a second look might well revise that finding. Certainly, some of the local populations have declined steeply in recent decades....
MORE: https://www.forbes.com/sites/michaelmars...our-fault/