With the change in water temperature due to global warming many species of salmon are perishing. Yet, a small group of them have evolved to become superfish to navigate the warming waters.
Nestled in the Frasier River of British Columbia, the river contains more than 100 different types of sockeye salmon. Due to climate change making the water warmer some fish are doomed. It is believed that salmon that migrate to these waters may be best suited to cope in the warming water.
Since the 1950s the Fraser River has heated up by nearly 2 degrees Celsius, and salmon migration rates have neared 95 percent in some populations of salmon during the warmest years. There are numerous studies showing the correlation between temperature and morality. The findings suggest that fish that do survive have larger and stronger hearts compared to those that perish.
Before swimming up the Fraser River to reproduce and die, millions of sockeye salmon spend their three to four year lifespan in the ocean. Experiments were done with eight different salmon populations out of the Fraser river, studies found that all of the fish analyzed and dissected revealed to have the most healthy cariorepiratiory systems and largest hearts compared to other fish.
The strongest of the salmon were found to be members of a population called Chilko, they came out the strongest in experiments to be deemed super fish. The weakest salmon were the Weaver sockeye their cardiovascular system gives out during the swim in the warmer waters. This leaves scientists wondering if the adaptation of the Chilko salmon to spawn so far upstream and navigate in a wide variety of water temperatures, could also occur in other salmon species as a response to climate change. Scientists would like to study the dates of this evolution so they have an idea how quickly salmon can evolve and if they will be better able to cope with current warming trends.