Tag Archives: Climate Change

Fishing in the Extremes

A recent poll of anglers and hunters shows that 66 percent of us believe we have a moral responsibility to confront global warming to protect our children’s future.  Interestingly, only 59 percent of sportsmen actually agree that global warming is occurring, according to the poll taken by the National Wildlife Federation.  These numbers imply that 7 percent of sportsmen think something should be done to curtail global warming, even if they don’t believe it is actually happening.  For some commentary from a seemingly representative demographic of sportsmen, check the blog comments on a recent Theodore Roosevelt Conservation Partnership video and post

Here’s another statistic on climate change. Last week, the National Snow & Ice Data Center in Boulder reported that on September 16 arctic sea ice cover reached a historic low.  This breaks the previous “minimum extent” record set in 2007 and is nearly 50 percent lower than the average coverage between 1979 and 2000.

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An image of the Arctic sea ice on September 16, 2012, the day that the National Snow and Ice Data Center identified to be the minimum reached in 2012. The yellow outline shows the average sea ice minimum from 1979 through 2010. (NSIDC)

Despite this and other evidence of climate change, 41 percent of sportsmen are still skeptical. Understanding climate change isn’t easy because it involves some seriously complex science. But for the sake of fish and wildlife habitats everywhere, I will do my best to explain what is going on, and what it means for the fish.

Recent trends in the weather provide a great example of extreme weather events that result from climate change. As recently as September 25, the US Drought Monitor showed that 65 percent of the contiguous US is in some form of drought.  A year ago, this number was just 30 percent. In the West it is even worse, with 77 percent facing drought vs. 19 percent a year ago.

Winter weather has been extreme in recent years as well.  If you like to play in the snow, you’ll recall that the most recent Colorado ski season was one of the worst some have ever had, with the lowest snowfall levels in 30 years.  This is a stark contrast from 2010-2011 season when snow sports enthusiasts reveled in the record snowfall of 525 inches.

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Credit: bigblueglobe.blogspot.com

Anglers certainly felt the effects of these extreme weather events. Last spring and summer brought record runoff that made many rivers and creeks look like chocolate milk.  This summer, low flows and high water temperatures forced voluntary bans in some areas, including the Yampa in Steamboat.

It is true that rapidly changing weather conditions are more the rule in the Rockies than the exception, “just wait 10 minutes” if you disagree.  But this level of volatility in the climate (which is weather over the long term) isn’t part of the typical pattern.  Further, climate scientists believe that climate volatility and extremes will increase with climate change. That isn’t good for the fish, and it isn’t good for anglers.

For example, consider the implications of the cutthroat trout, the most diverse trout species in North America and a true Colorado native.  “Cutties” are already facing pressure from non-native species like rainbow, brown and brook trout.  According to hydrologic models developed by Trout Unlimited, the US Forest Service, and others, cutthroat trout are expected to lose as much as 58% of their habitat under climate change.

In comparison, “brookies” are predicted to lose 77% of their suitable habitat, browns 48%, and rainbows 35%.  In total, suitable habitats for any four of these species is predicted to decline by 47%.  It’s hard to imagine what fishing would be like if climate change eliminated nearly 50% of our fishing spots.

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This plot shows the length of predicted suitable habitat for four species of trout under current conditions and under climate-change scenarios for the 2040s and 2080s. Source: Trout Unlimited.

So what is actually causing these projected declines in habitats?  In short, climate scientists expect warm and dry climates to become even warmer and dryer under climate change. Declining snowfall levels and rising temperatures as a result of climate change will make the already arid Southwest even drier.

Specifically, they predict lower winter precipitation levels.  When winter precipitation does occur, rising temperatures will cause more of it to fall as rain, meaning even less snowpack to fill our streams in the spring.  Additionally, rising temperatures also mean earlier and faster snowmelt.  Recall how the rivers looked during record runoff of spring 2011 that spiked flows substantially and made fishing much more difficult.

The arctic ice (or lack thereof) plays a part in all of this too.  Like the cubes in your iced tea, the earth’s ice helps keep us cool, no matter where you live.  As NSIDC lead scientist Ted Scambos said, “This will gradually affect climate in the areas where we live…we have a less polar pole—and so there will be more variations and extremes.”

Though extreme fly fishing sounds like fun, 50 percent less fish habitat is definitely not an extreme I’d like to live with.