Bio Acoustic Fish Fence May Protect Great Lakes

A bio acoustic fish fence (BAFF) is being tested on a tributary about 200 miles from Chicago by ecologist Gregg Sass. The BAFF is basically an underwater sonic fence; a barrier created by outputting sounds into a wall of bubbles.

The intent is to stop invasive Asian carp species from swimming up the Illinois river and reaching the Great Lakes, which already have enough problems.

It uses an air bubble curtain to contain a sound signal which is generated pneumatically. Effectively, this creates a "wall of sound" (an evanescent sound field) field that can be used to guide fish around river structures by deflection into fish passes.

Physically, the BAFF comprises a pneumatic sound transducer coupled to a bubble-sheet generator, causing sound wave to propagate within the rising curtain of bubbles. The sound is contained within the bubble curtain as a result of refraction, since the velocity of sound in a bubble-water mixture differs from that in either water or air alone.


(An effervescent wall for fish)

1. Inside a shed on the riverbank, a signal generator emits eight chirps at varying intervals and varying frequencies up to 2,000 Hz. Two 400-watt amplifiers pump up the beeps to carp-deafening levels.
2. A compressor pushes a continuous stream of air through a rubber pipe riddled with small holes. The pipe, housed in an open steel chassis, runs across the bottom of the riverbed.
3. The pipe releases a sheet of bubbles illuminated by strobe lights flashing 200 to 400 times per minute. Alongside the pipe, 16 hundred-watt sound projectors shoot the chirping sounds into the fizz, where the noise is concentrated.
4. Native fish like trout and salmon can't hear frequencies above 400 Hz and swim through the bubbles unfazed. Carp, which perceive sound as high as 2,000 Hz, hit the piercing noise and turn back.

The first place I read about this idea was in Roger Zelazny's 1976 novel My Name is Legion; he refers to sonic curtains that can be used to keep sharks out of selected areas in underwater parks. Amusingly, dolphins can be taught to use it, and in turn teach other dolphins.

From Wired via Neatorama. See also this article on the fish fence.

Scroll down for more stories in the same category. (Story submitted 8/16/2009)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 0 )

Related News Stories - (" Engineering ")

Stick-On Tape Speakers, As Predicted By Bruce Sterling
Flexible tape speakers, someday.

Has Climate Change Already Been Solved By Aliens?
'I had explained," said Nessus, "that our civilisation was dying in its own waste heat.' - Larry Niven, 1970.

Skin Electronics 3D Printed
'June's body is a tracery of lambent lines, like some arcane capillary circuitry...' - Paul Di Filippo, 1985

Super-Resolution Microscopy Provides '4D' Views
View the magnified interior of living cells.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

Sleeep PRO Earplug For Maximum Rest
'Merton... placed the electrodes of the sleep-inducer on his forehead.'

Inspired By Japan, Nap Pods For Hajj
It's always a good time for a nap.

Amphibio 3D Printed Gill Shirt
'... we can descend and live down there at one of those year-round aquatic resorts.'

How Do You Put An Asteroid Into Earth Orbit? Carefully!
'...she would have to be coaxed by another series of pats into a circular orbit.'

PD Aerospace Space Plane By 2023
'The sleek, tapered space shuttle lay immobile upon the private landing field...'

Foldimate Folds Your Clothes Perfectly
Look ma, my room is clean! I can hear you now.

Robots Help People Get Dressed, As Predicted In 1931
Yes, people of the future, robots will dress you.

International Space Station Leak Plugged - With Finger
'These tag-alongs search out stray leaks.'

Robot Snake Flies, Fights Fires
Just a prototype, but still amazing.

IPAL Chinese Robot Babysitter
'But Nanny is different...'

ZKZM-500 LASER Assault Rifle
'The Iranian reached back into the locker and got a pair of laserifles.'

LA Subway Scanner, As Seen In 'Total Recall'
'I'm afraid to tell you this Mr. Quaid, but you have suffered a schizoed embolism...'

Sion Electric Car Covered With Solar Panels
'It drew its power from six square yards of sunpower screens on its low curved roof.'

PAL-V Liberty Flying Helicopter Car
'...lifted themselves to skimming flight upon whirling helicopters."

Space Drones - UK's Effective Space To Launch Rocket Tugs
'Twenty rocket tugs towed it from its Earth hangar out into space.'

DIY Autonomous Robot Detects Trash
'The search-bug detached itself and rolled forward.'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.