Rutgers Blasting off of Long Beach Island

[njdiver]

Decibel level in water has a different measurement than in air! “The decibel is a relative unit of measure, not an absolute one. Confusion arises because relative intensities in water are referenced to 1 microPascal (µPa) whereas sound waves in air are referenced to 20 microPascals (µPa). The intensity of a sound wave depends not only on the pressure of the wave, but also on the density and sound speed of the medium through which the sound is traveling. Therefore, relative sound intensities given in dB in water are not the same as relative sound intensities given in dB in air.”

http://www.dosits.org/factsandmyths/ (#11)

For more detail:

http://www.dosits.org/science/soundsinthesea/airwater/

[Gerry Zagorski]

I'm all for research but this is being done in the middle of the fishing season ??

[njdiver]

Originally Posted by Gerry Zagorski

I'm all for research but this is being done in the middle of the fishing season ??

The vessel's schedule (also involved with surveys of Outer Continental Shelf) and Rutgers staff's availability. They explain it in their Final Environmental Assessment:

http://www.nsf.gov/geo/oce/envcomp/n...2015-final.pdf

[mikeytheflop]

This is what I took as most important from the Rutgers report:

... concluded that seismic surveys could cause temporary, localized reduced fish catch to some species, but that effects on commercial and recreation fisheries were not significant. Most commercial fish catches by weight (almost all menhaden) and most recreational fishing trips off the coast of New Jersey (87% in 2013) occurred in waters within 5.6 km from shore, although the highest-value fish (e.g., flounder and tuna) were caught farther offshore. The closest distance between the proposed survey and shore is >30 km, so interactions between the proposed survey and recreational and some commercial fisheries would be relatively limited.

My opinion = no effect.

[njdiver]

R/V Marcus G. Langseth. She is on the move! Presently in the East River going under the Manhattan Bridge heading South.

[Down Deep Sportfishing]

Amazing, you can't piledrive in Jan. because of winter Flounders, but they can blast in prime fishing time in the name of research.

[shresearchdude]

"This is what I took as most important from the Rutgers report:

... concluded that seismic surveys could cause temporary, localized reduced fish catch to some species, but that effects on commercial and recreation fisheries were not significant. Most commercial fish catches by weight (almost all menhaden) and most recreational fishing trips off the coast of New Jersey (87% in 2013) occurred in waters within 5.6 km from shore, although the highest-value fish (e.g., flounder and tuna) were caught farther offshore. The closest distance between the proposed survey and shore is >30 km, so interactions between the proposed survey and recreational and some commercial fisheries would be relatively limited.





(a) Location of the Activity
The proposed 3-D box/survey area is located in the Atlantic Ocean, ~33–92 km off the coast of New Jersey and 27–87 km from New Jersey state waters
(Fig. 1). This area is defined by the coordinates at the four corners (including turns and run-in and run-out of each line) in degrees and decimal minutes:
39°38.00’N, 73°44.36’W; 39°43.12’N, 73°41.00’W; 39°25.30’N, 73°06.12’W; and 39°20.06’N, 73°10.06’W.

[Ahab123]

I emailed Rutgers with a complaint and this is the response
I got.....


Dear Scott,

Thank you for writing to me and expressing your concern about the
National Science Foundation-funded project to use acoustic images to map
the ocean floor to better understand sea level rise. The project is a
collaborative effort involving several universities, with the federal
funding from the NSF.

The project is operating in accordance with regulations established by
the U.S. Marine Mammal Protection Act, Endangered Species Act, and
National Environmental Policy Act. Its permit applications were twice
approved by fisheries biologists and endangered species experts with the
U.S. Fish and Wildlife Service and the U.S. National Marine Fisheries
Service.

Ship operations follow strict protocols to minimize disruption to marine
wildlife. Five specialists in the behavior of marine species, who have
no association with the scientists or their research, will be on board
for the entire cruise to listen, watch, and record the behavior of
marine species 24/7. If marine mammals or turtles come within a
designated radius of the ship, its sound sources will be turned off
until the animals leave the area.

Sincerely,

Robert Barchi

[Hunter 2]

Originally Posted by njdiver

R/V Marcus G. Langseth. She is on the move! Presently in the East River going under the Manhattan Bridge heading South.

Correct I saw her moving out from Brooklyn bridge towards the harbor. I'm working in the building behind South Street Seaport.

[Joey Dah Fish]

Originally Posted by njdiver

Decibel level in water has a different measurement than in air! “The decibel is a relative unit of measure, not an absolute one. Confusion arises because relative intensities in water are referenced to 1 microPascal (µPa) whereas sound waves in air are referenced to 20 microPascals (µPa). The intensity of a sound wave depends not only on the pressure of the wave, but also on the density and sound speed of the medium through which the sound is traveling. Therefore, relative sound intensities given in dB in water are not the same as relative sound intensities given in dB in air.”

http://www.dosits.org/factsandmyths/ (#11)

For more detail:

http://www.dosits.org/science/soundsinthesea/airwater/

Sounds like you are very informed. I would like to ask a question. Does sound travel further in water? Does water magnify sound waves?