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From time to time, I disagree with different issues that various organizations support. The scheduled seismic testing is one of those.

When the tests were announced, I was contacted by several other organizations including Ocean County Government asking for my opinion. I deferred giving my opinion until I did some research on my own. Here's a synopsis of what I found:

Air guns used in seismic testing generally create about 300 db at the gun. Within 1/4 mile, the level has reduced to less than 100 db. The quantity of air expelled from each gun is about 1 quart before compression. The sound from the air release lasts a fraction of a second.

Let's compare that information to the latest recreational fish finders including my new Garmin machine. In sounders the power is generated within the transducer but the sound waves effectively work exactly the same. My new sounder will "ping" twice per second using a fraction of a second pulse length, similar to the air guns. At maximum power, generally used only in the deepest water, the output is 3,000 watts. Compared to older machines, this is a big increase. The sound is in the same frequency range as that created by air guns. The decibel level of full 3,000 watt transmissions is just under 300 db at the transducer but lasts but a fraction of a second for each "ping."

Further, the ocean is a noisy place with the noises coming from animals as well as people. Scientists have a great deal of proof that many types of whales, including whale species found in our area, exceed 300 db when they sound off and they sound off for a period that is measured in multiple seconds not milleseconds. Whale calls can be heard for many thousands of miles and are a major cause of interference in a variety of underwater sound including military, research plus commercial and recreational fishing but don't seem to bother other sea life.

There has been a good deal of research in what interaction loud sounds cause with marine life. The finding that stood out as the most important is that few porpoise/dolphins seemed to be bothered by sound signals in these frequency ranges. Whales who seemed bothered simply move away between a half-mile and one mile and resumed their activities. Small marine creatures and fish did not seem to be bothered. We have witnessed marine mammals when seismic testing was operating in the area.

Engineers working for the U.S. Navy, my son-in-law is one of those, and the senior engineers at Airmar, the largest transducer manufacturer, and at Garmin all noted that the seismic, military and fishing users generally use similar frequency ranges at similar power as seismic testing air guns if they were using maximum power. The Navy said that their units normally work in ranges that require about 1,400 watts. New sounder equipment is far more sensitive on the receiver end than older generation units. The frequency range is generally 28 kHz to 125 kHz. My new equipment uses 28 kHz to 75 kHz in the low band and 130 to 210 kHz in the high band.

All of the engineers said that today's seismic, military and fishing users use receivers that are far more sensitive than what was used before. Whereas some years ago, the older technology simple used more wattage to generate signals so that the receivers of the day could adequately hear the reflected sounds. The engineers went on to say that instead of today's equipment "pinging" many times per second as older equipment does, the new equipment pings fewer times per second, as per the new Garmin equipment, and that gives more time for the receiver to read the reflected sounds.

I have been around seismic test ships over the years. None of us heard anything from the air guns. The sounds were focused down into the water at various angles. Neither did we see any disturbance of the water when the air guns fired.
Large air chambers in seismic air guns (i.e., greater than 1.15 L or 70 cu in) tend to give low frequency signals and the smaller chambers (less than 70 cubic inches) give higher frequency signals. See the attached picture of an air gun firing in a small pool.


Here's a 30 Liter air gun, generally the largest used. Most are far smaller. That is not a lot of air. One liter contains a little over 61 cubic inches so a 30-Liter gun would hold about 1,830 cubic inches of pressurized air.





The only thing that happened on those days around the seismic ship was listening to the repeated warnings from the seismic vessel to stay away from their towed equipment that was as far as 1 nm behind the ship. Very time we saw them, we could see the end of their tow since it has what looked like a water ski flag at the end of the tow. One day, we were in the Toms and a seismic ship was there all day just running a lawnmower pattern. Whales were there too and many got well within a half mile of the seismic ship and did not seem frightened. Many had babies with them. Porpoise were all over the place and we caught a limit of Yellowfins, a load of Mahi and released one White Marlin that day.


I would point out that many organizations who are objecting use language such as "blasting, disrupt, harm, annoy, boom, shots, injure, kill" and other words that incite people to take action against seismic surveys. I strongly disagree with their tactics and I believe that they are misguided in their actions. None of their PR materials cite scientific findings, only subjective language.

Remember that we had oil rigs in the Atlantic off New Jersey from about 1978 through 1982. Several were in and around the bottom of the 40 Fathom Fingers and one was in the Toms. We fished around those rigs and never once saw any sheen or other evidence of pollution in the water. We caught tons of fish near the rigs. Our opinion of the operations was that they were staying well within the rules and were doing a tough job very well without any ocean pollution whatsoever. The rig that spent most of the period around the 40 Fathom Fingers was operated by Amerada Hess. By the way, back then, they didn't find much oil but they did find gas. The price at the time was simply not high enough to build the collection network and to pipe it to shore.


Many of the seismic objectors object since they disapprove of the oil and gas industry in general. Personally, I hope the search for oil and gas hits it big off the New Jersey coast so we have plenty of well-engineered, well-operated rigs out there to fish around. It's sure a lot better than wind farms that cost a fortune in taxpayer subsidies to make them viable.

As far as the seismic objectors, they must not be ready to give up their Volvos since Volvo sales are up this year.
 

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Capt. Lindsay

I will not be down to the boat until this weekend but I believe I still have the marks on the paper chart as to where the rigs were. If I remember right coming out of Barnegat, we used to hit the first one about 50 miles off shore, then there was one at the Toms Canyon, one up on the Elbow and then one closer to the tip of the Hudson.

I had a good friend who had a pretty big job at Exxon at the time, he said money was not right. He told me the geoligist told them there is oil there. They did find oil but not enough at the time and the price was only around 25 a barrel so they really had no interest in drilling to look for it. He said when the the geoligist tell them it is there, they will drill 100 dry holes looking for it.

It was just about money. There is plenty of oil off of NJ and they all know it. Now it is the environmentalist who will stop it.
 

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Great read Capt. Lindsay !

You just cleared up all the rummers. I didn't think they would do this if it was going to cause all those problems i was reading about.

I will pass this info along. :)
 

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Thanks for your opinion. I think a major part of the argument is the timing. This should only be done in the winter!
 
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