All about the bass...
All about the bass
Montana’s rivers
are warmer than they should be, which is bad news for trout
Jul 16th 2016 |
LIVINGSTON, MONTANA | From the print edition
Hotter than July
STANDING on the
banks of the Yellowstone river in southern Montana on the last afternoon in
June, Dan Vermillion gazes at the clear, sun-dappled waters, checks the river
temperature on his smartphone, and pronounces the conditions “great fishing”.
Alas, this does not cheer Mr Vermillion, who grew up fishing these waters for
trout and now works as a high-end outfitter, guiding the wealthy and powerful
to the world’s best fly-fishing spots, from Montana to Alaska and even
Mongolia. For these fine fishing conditions—with the water running clear after
months of turbid flows from spring snowmelt, and the temperature at 65°F
(18.3°C)—have arrived too early, by some weeks. The water should be ten degrees
cooler, frowns Mr Vermillion, and data retrieved by his smartphone from a
nearby measuring station shows flows at less than half their historical median
level.
All rivers vary
from year to year. What worries federal wildlife officials, state biologists
and a growing number of devoted anglers across the mountain West, is that, for
the past 15 years, some of America’s finest fishing rivers keep breaking
records for early snowmelts, too-warm water and low flows. Mr Vermillion is
also chairman of the Montana Fish and Wildlife Commission, a government body.
To his dismay he has just approved some of the earliest fishing closures ever
recorded, closing legendary trout waters on such rivers as the Gallatin,
Beaverhead and Jefferson every afternoon with effect from July 1st, after water
temperatures hit 73°F (22.8°C) on three consecutive days. Afternoon closures
are a compromise, aimed at giving trout a respite in the warmest hours of the
day. Trout are cold-water fish, which struggle to digest food above such
temperatures, and start to die once water nears 80°F (26.7°C). Warmer water
carries less oxygen, too, so that trout caught and released may never recover
once back in the river.
Such worries used
to be rare. In the six years from 1995 to 2000 water temperatures on the
Jefferson river, in south-western Montana, exceeded 23°C on only 23 days, and
in some years never went that high. In 2015 alone, the water crossed that
danger-mark on 21 days and exceeded 26°C in early July, leading to significant
fish deaths. After studying data going back decades, the long-term trends are
“exceptionally clear”, says Mr Vermillion. Other signs of stress may be seen.
The coldest, highest rivers of south-western Montana are home to the
Yellowstone cut-throat trout, named after an orange under-jaw marking like a
slash. Smaller than non-native rainbow and brown trout, which were introduced to
Montana in the 19th century, the cut-throat is especially sensitive to warming
water. Rainbow and brown trout are pushing up into cut-throat fisheries, even
into the protected rivers of Yellowstone National Park, where anglers must
watch for grizzly bears and snorting, shaggy-headed bison, but increasingly
catch hybrid trout, rather than pure-bred cut-throats. Worse, smallmouth bass,
a warm-water species, are each year creeping farther and farther up Montana’s
rivers. Bass have even been caught near Mr Vermillion’s office in the handsome
town of Livingston.
Something, in
short, is going on. Where consensus breaks down is when locals, scientists,
politicians and even fishing clients debate whether what is going on has links
to man-made climate change. All too often discussions follow partisan lines,
says Mr Vermillion. He is a Democrat in a conservative state: his office wall
has a photograph of him fishing with President Barack Obama in Montana (“Dan!
You got me hooked,” reads the presidential inscription). His wife’s family, who
are conservative farmers, acknowledge that the weather is changing. “Where it
gets tricky for them is to admit that it is man-made.” Montana’s three-man
congressional delegation splits on party lines: Representative Ryan Zinke and Senator
Steve Daines, who are Republicans, call the science of climate change far from
proven, and both have opposed carbon-emissions curbs that might hurt their
state’s coal and oil industries. Senator Jon Tester and the governor, Steve
Bullock, both conservative Democrats, call climate change a threat and back the
development of renewable energy in Montana (a windy place), while urging
caution over federal policies that would impose rapid change on the coal
sector.
Spending by
tourists is increasingly valuable, with the state Office of Tourism claiming
that 53,000 jobs are supported by visitors. Mining employs fewer than 7,000
people in a state of 1m inhabitants. But coal and oil jobs pay better than
tourism work, and energy companies pay a lot of taxes. Still, fish are changing
the public discussion about climate change and whether it might be hurting
Montana, says Mr Vermillion, who as a wildlife commissioner meets frequently
with hunters, ranchers and other groups. Telling people where smallmouth bass have
been found is his most effective piece of evidence for convincing audiences
that the weather is changing, he notes, trumping dry statistics about rising
temperatures, shrinking snow packs and more frequent wildfires. “What
bass say about our rivers is spooky.”