Cold mountain streams may offer a type of refuge from climate change. Scientists discovered that these areas could offer cold-water species a habitat in the face of changing temperatures.
In this latest study, researchers looked at stream temperatures in the northwestern United States, using data from huge stream-temperature biological databases. They found that over that last 40 years, stream temperatures have warmed an average rate of .18 degrees Fahrenheit per decade. This means thermal habitats that are sensitive to temperature have shifted upstream about .18 to .31 miles per decade.
"The great irony is that the cold headwater streams that were believed to be most vulnerable to climate change appears to be the least vulnerable," said Daniel Isaak, lead author of the new study. "Equally ironic is that we arrived at that insight simply by amassing, organizing and carefully analyzing large existing databases, rather than collecting new data that would have been far more expensive."
So what does this mean? It looks as if the shifts due to climate aren't all that large. In addition, species can find a type of refuge in colder mountain streams. This is particularly important when it comes to seeing which species are more likely to survive under changing conditions.
"One of the great complexities of restoring trout and salmon under a rapidly changing climate is understanding how this change plays out across the landscape," said Jack Williams, senior scientist for Trout Unlimited. "Dr. Isaak and his colleagues show that many mountain streams may be more resistant to temperature change than our models suggest and that is very good news. This provides us more time to effect the changes we need for long-term persistence of these populations."
The findings are important for future conservation efforts. More specifically, they show that resource managers will have time to complete surveys of stream ecosystems so that they can create better strategies to adequately address all species that may be impacted by climate change. It also shows that these ecosystems are more resilient, which means they may be able to better adapt to future changing conditions.
The findings were published in the April edition of the journal Proceedings of the National Academy of Sciences.
