Non-physical Barrier |
| Experimental Non-Physical "Bubble" Barrier at the confluence
of the San Joaquin River and Old River. Used in 2009 to prevent juvenile salmon swimming
down the San Joaquin River to the ocean from going into Old River. Past studies have
shown that salmon kept in the main stem of the San Joaquin River have better survival
than those that move into the central Delta through Old River. Barrier combines
acoustics and a strobe-lit curtain of bubbles to create an underwater wall of light and
sound at frequencies that repel juvenile Chinook salmon. |
Shot 4/22/09 showing barrier and safety markers. |
Contractor assembles metal frames that hold the equipment. |
Prefabricated PVC pipes for the air supply for the bubbles. |
Metal frames were fabricated with hinged ends to allow for uneven riverbed. |
Custom U bolts attach frames to piles or pile blocks. |
Red hoses deliver air from supply pipes to bubbler hose. |
Pile bocks hold frames in place on riverbed. |
Barge placed 4 pilings in alignment across Old River Mouth. |
4 pilings anchor barrier frames at set positions. |
Looking north along barrier alignment. |
Sound Projectors, special underwater speakers used to produce sounds of specific frequencies know to deter salmon. |
Checking LED strobe tubes for installation. |
Sound Projectors and strobe tubes installed on frame. |
Contractors install sound projectors, strobe tubes, air supply pipe and wiring harness with components for sound and light. |
Installed wiring harness with components for sound and light. |
Contractors install sound projectors, strobe tubes, air supply pipe and wiring harness with components for sound and light. |
Looking north at barrier location showing safety ball buoys. |
Inspecting bubble hose. |
Bubble hose, consisting of two parts, larger is weight and smaller has bubble hose and is supplied with air. |
Completed frame showing (back to front) air supply pipe, wiring harness, sound projector, LED strobe tubes and double bubble hose. |
Wire to provide power, sound signal and control to frames from control box. |
Completed frames ready to attached to pilings and lowered into river. Note the air supply pipe with hoses to bubbler hose and purge valves below. |
Safety and planning meeting prior to installation of frames. |
Safety and planning meeting prior to installation of frames. |
Wiring control boxes to frames for testing prior to installation. |
Testing LED strobe tubes. Note they are lit up. |
Splicing control wires to wire harnesses on frames using waterproof seals. |
Sunrise Saturday morning ready to install barrier frames in the river. |
Using a spreader, barge mounted crane lifts the first two frame sections of barrier. Note two frame sections of eight meters each are installed at a time. |
Barge moves into position. |
Frames lowered into position. |
Tenders assist diver along river bottom to place barrier frames. |
Diver help crane to lower barrier frames into correct alignment and connects fittings for air. |
Crane lowering barrier. |
Next sections of frame being prepared for placement. |
Warning signs for boaters and fishermen. |
Aerial of site looking east. |
Aerial of site looking north. |
Aerial showing last pair of frame sections being placed on riverbed. |
Aerial showing last pair of frame sections being placed on riverbed. |
Trailer and portable buildings to house scientists and technicians to operate and study Bubble Barriers effects. |
Control cables and air supply pipes snake down riverbank to Bubble Barrier. |
Test of first section of Bubble Barrier in operation. |
Pressure reduction manifold delivers air at proper operational pressure to Bubble barrier in background. |
Compressors for air supply for Bubble Barrier. |
Bubble Barrier looking north along alignment. |
Close up of bubbles. |
Shot of alignment showing piles and safety equipment. |
Control equipment in temporary building. |
Scientist checking test equipment. |
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