Penn State
When trying to explain the potential effects of climate change
on plants, fish and wildlife, scientists usually resort to language that fails
to convey the impact of warming. Now, a study by Penn State's College of
Agricultural Sciences fisheries researchers clearly explains the impact of
projected warming waters on wild brook trout in the eastern U.S. for fishermen.
The eastern brook trout is a socially and economically important
fish that occurs in small cold water streams and lakes, and self-sustaining populations
support angling throughout the Appalachian Mountains, from Maine to Georgia.
However, warming air temperatures are expected to reduce available cold-water
habitat and result in a smaller brook trout distribution and fewer angling
opportunities.
Building on recent research at Penn State, Tyler Wagner, adjunct professor of fisheries and Tyrell DeWeber, now a postdoctoral scholar at Oregon State University, used two models they previously developed, one predicting stream temperature and one predicting where brook trout might occur, to identify streams likely to support wild brook trout under current and future climate scenarios.
The researchers then calculated the distance required to drive
from the centers of 23 cities spread throughout the eastern brook trout range
to the 10 nearest stream segments likely to have wild brook trout under current
and future conditions. They published their study in a recent issue of Fisheries.
"Climate change is expected to result in widespread changes
in species distributions for freshwater fish species. Although anglers and
other resource users could be greatly affected by these predicted changes,
changes are rarely reported in ways that can be easily understood by the
general public," said Wagner, who is assistant unit leader of the
Pennsylvania Cooperative Fish and Wildlife Research Unit at Penn State.
The effects of climate change on fish and wildlife are usually
reported to the general public using summary metrics or maps designed to
communicate concepts that are not normally encountered in everyday life,
including changes in habitat suitability, range shifts, or increasing risks
from disease or extreme events, according to Wagner.
"Though these metrics
are necessary, meaningful, and understood by scientists, many people lack the
necessary training and background to readily understand them."
"Further, scientists and nonscientists alike may struggle
to convert these metrics into a currency that directly affects day-to-day life.
Climate science is a complex issue, and when we communicate potential responses
of vegetation, fish and wildlife to nonscientists, creative thinking with
respect to the currency of communication will facilitate discussions between
scientists, policy makers and the public."
DeWeber, who was a doctoral student at Penn State when the
research was conducted, noted that travel costs based on distance have been
widely used to value ecosystem services such as angling under climate-change
scenarios, but have not been used for communicating potential changes to the
public, despite the intrinsic link to everyday life.
"Under current conditions, brook trout are predicted to
occur in streams throughout the region, and average driving distances from
cities to the nearest streams predicted to offer angling opportunities ranged
from 4 to 87 miles. As a result of projected warming, driving distance to go
fishing for wild brook trout was predicted to increase, on average, by almost
164 miles over the next 70 to 80 years."
For example, the driving route from Philadelphia to the nearest
brook trout stream was predicted to cover 249 miles in a warmer future, much
longer than the current 48 miles.
The lengths of trips from many northern cities, such as Bangor,
Maine, were predicted to increase but were still relatively short in the future
because nearby streams were still predicted to support brook trout under warmer
conditions.
In contrast, anglers in southern cities, such as Cleveland,
Tennessee, would experience dramatic increases in the lengths of trips because
brook trout are predicted to be lost in surrounding areas.
Although anglers tend to be very dedicated, DeWeber pointed out,
it is unlikely that many would drive great distances to fish very often due to
cost, especially if those last remaining streams become popular and crowded. He
believes that losses of wild brook trout populations and increased trip lengths
would likely result in reduced resource use in many areas.
But he suggested that people are unlikely to be concerned about
the potential effects of warming if they do not understand what may be coming.
"Communicating species responses to climate change in everyday language
could greatly increase the ability of resource users and other members of the
general public to understand and relate to predicted changes," he said.
"A clear understanding of potential changes might not lead to greater
societal concern about species' responses, but it may enable people to make
informed decisions."
