https://hakaimagazine.com/features/light-at-the-end-of-the-tunnel/
"Every year, hundreds of muscular, sea-bright fish—chum salmon, chinook, coho,
steelhead—push into the Columbia River from the Pacific Ocean, swim over 200
kilometers upstream, and turn left into Hardy Creek. They wend through rocky
shallows shaded by alder and willow, cold water passing over flared gills.
Plump with milt and eggs, they pump their tails furiously, striving for the
graveled spawning grounds in southern Washington State where they’ll complete
their life’s final, fatal mission.
And then they hit the railroad.
In the early 1900s, Hardy Creek was throttled by BNSF Railway, the United
States’ largest freight railroad network. When the company built its Columbia
River line, engineers routed Hardy Creek under the tracks via a culvert—a
2.5-meter-wide arch atop a concrete pad. The culvert, far narrower than Hardy
Creek’s natural channel, concentrated the stream like a fire hose and blasted
away approaching salmon. Over time, the rushing flow scoured out a deep pool,
and the culvert became an impassable cascade disconnected from the stream
below—a “perched” culvert, in the jargon of engineers.
“It’s an obvious barrier,” says Peter Barber, manager of the Cowlitz Indian
Tribe’s habitat restoration program. “A fish would be hard-pressed to navigate
through that culvert.”
The strangulation of Hardy Creek is an archetypal story. Culverts, the
unassuming concrete and metal pipes that convey streams beneath human-made
infrastructure, are everywhere, undergirding our planet’s sprawling road
networks and rail lines. Researchers estimate that more than 200,000 culverts
lie beneath state highways in California alone, nearly 100,000 in Germany, and
another 60,000 in Great Britain. In Europe, they thwart endangered eels; in
Australia, they curtail the movements of Murray cod. In Massachusetts’ Herring
River, snapping turtles lurk in culverts to devour passing fish, largely
preventing herring from spawning. Taken as a whole, these obstacles are a major
reason that three-quarters of the world’s migratory fish species are
endangered.
Compared with dams, however, culverts have historically escaped public
attention; most people drive over them every day without noticing. “I used to
tell people I assess culverts,” recalls Mark Eisenman, a planner at the Alaska
Department of Transportation. “They’d say, what the hell’s a culvert?”"
Via
Fix the News:
<
https://fixthenews.com/good-news-malaria-india-tolerance-africa-deforestation-brazil/>
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
