Seismic surveys may kill giant squid


16:58 22 September 04

NewScientist.com news service

http://www.newscientist.com/news/news.jsp?id=ns9999643774

:shock:

:shock:

... the link is temporarily down; cannot wait to view this one (I knew nothing about it)!!

Here's another link:
http://www.newscientist.com/news/news.jsp?id=ns99996437

My word - how bizarre!! How very, very bizarre, and how interesting that various organs have been damaged internally ..... Need a head-scratching emoticon. Need to ponder this one. Ta M!

I thought this was going to be about Seismoteuthis :wink:

:shock: :shock:

"badly damaged EARS"??????? I assume they mean the statocyst chamber??

J

That's disturbing news, though it certainly makes sense that the shock waves would have an adverse effect. The question now is, will the people doing the blasting stop?

As far as the emoticon is concerned, how about this? http://protask.nl.eu.org/~dennis/emoticons/conf36.gif

--Carl
http://protask.nl.eu.org/~dennis/emoticons/div34.gif

As far as the emoticon is concerned, how about this? http://protask.nl.eu.org/~dennis/emoticons/conf36.gif

--Carl
http://protask.nl.eu.org/~dennis/emoticons/div34.gif
I like!

J

Do you think there is a link between what is suggested Steve? My initial reaction is that it is a bit of a jump...

It's a tough one C; it is quite possible, similar in fact to how the sperm whale might immobilise prey in order to catch it.

I must admit that the only cephalopod remains I have seen (from the stomach contents of sperm whales) are beaks. But from what I've read, and based on the photographs that I've seen, large squid as a rule seem to be intact, or effectively so (some without the head, others without the mantle, but without tooth marks on either end). The danger is that people are less likely to take photographs of mushed up squid from the stomachs of these things than they are to take pics of entire and very large squid, so that we get a rather biased picture of what is going on (large/intact squid might not be the norm).

The sonar/underwater detonation could have a similar effect on squid as a whale's sound emision (we call this a 'sonar canon' in the latest AFO episode. In fact we dwell on this in the latest AFO (the colossal squid/whale episode), and we also talk about frequency and squid reaction to certain frequency (ranging from attraction to alert, panic and death)). Although there's a lot of hype in the programme, there's a lot of science in there as well .... We also put a real squid in the jaws of a mechanical sperm whale and try and eat it without putting a tooth mark in it .... and it can't be done (so the whale couldn't be using the 'jaw' as a feeding aparatus; it is possibly immobilising/killing prey with the 'sonar canon' and then slurping it up. Recent evidence points to the whale actually consuming spent, dead or dying squid).

We do know that sonar has a serious effect on whales, and has been identified in a number of instances as the cause of strandings. The same could also apply to squid.

I'll keep an open mind on this NS article; he could be on to something.

IMHO it seems highly unlikely that the sonar blast on its own could cause significant organ damage - unless the poor wee beastie was investigating the air cannon at the time! As evidence, I cite the use of high volume, low frequency sound transmitted through water in order to destroy kidney stones without causing significant damage to the surrounding tissue. The machine is called a lithotripter I believe.

Perhaps they were disgorged from the stomachs of terrified sperm whales? ;)

There is a way to test this ....

If the whale is using a sonar cannon to immobilise squid prey, then the anatomy of squid recovered from the stomach contents should be damaged in a similar way.

There is a way to test this ....

If the whale is using a sonar cannon to immobilise squid prey, then the anatomy of squid recovered from the stomach contents should be damaged in a similar way.

But if the whale's sonar cannon simply daze and confuse the squid long enough to be caught/gulped by somehow disturbing statocysts then we might not see any damage.

Perhaps another way would be to submit squids to a range of frequencies... I hear we have some next door :twisted:

*saunters out...grabbing sonar cannon*

TPOTH

i dont quite get this, does the whale's sonar damage its own body organs or the squid's?

i dont quite get this, does the whale's sonar damage its own body organs or the squid's?

Supposedly/possibly the squid's

thats what i thought...but isnt the sonar sound? hows it suppose to hurt the squid. According to my AUZie penpal the whale has soundwaves of up to 223Db? WOuldnt that be louder than the blue and fin whale?Why isnt it writen anywhere, shoudnt it be the loudest animal..?

I've thought this was an interesting theory since I read about it in Richard Ellis' book. I think there is a huge already-collected data set that could be helpful in confirming or denying it: the US (and presumably other countries') navy has done extensive research in classifying sounds picked up by passive sonar systems. If sperm whales are producing sounds for hunting, it seems inevitable that they've detected and cataloged them. I expect if one could find the right people to ask in the navy, they'd be happy to make a positive contribution to cetacean science; if they get good press from that, it might make them more responsive about other issues in how their operations impact marine animals... (I've noticed that some environmental groups seem intent on villifying the navy, while most navy people I've talked to actually like marine life and are enthusiastic about opportunities to help researchers)

my main question is that, do you think the sperm whale's hunting sonar can reach 223Db?

I'm not a biologist by any stretch of the imagination, but I've worked with sound pressure levels (SPLs) in an engineering capacity, and 223 dB is awfully loud. :shock:

Here's a table I found listing comparative sound levels that includes a blue whale from this NOAA website (http://oceanexplorer.noaa.gov/explorations/sound01/background/acoustics/acoustics.html).:


Amplitude of Example Sounds In Air (dB re 20µPa @ 1m)
and In Water (dB re 1µPa @ 1m)

threshold of hearing 0 dB --
whisper at 1 meter 20 dB --
normal conversation 60 dB --
painful to human ear 130 dB --
jet engine 140 dB --
blue whale -- 165 dB (in water)
earthquake -- 210 dB (in water)
supertanker 164 dB (in air) 190 dB (in water)

*note - sounds are in air unless otherwise noted


Every additional 3 dB represents a doubling of power of acoustic energy.
223 - 165 = 58 dB which represents 19.3 doublings of acoustic power. :shock:

The sperm whale is a big animal which can probably make some very loud sounds if it wants to, but to reach 223 dB, it would have to be 58 dB louder than a blue whale.


Here's another table from the Ocean Future Society (http://www.oceanfutures.org/jmc/messages/lfa_qa.asp)


Noise Source Noise Source Levels

Lightening Strike on Water Surface 260 dB (max)
Seafloor Volcanic Eruption 255+ dB (max)
Fin Whale 160-186 dB
Humpback Whale 175-190 dB
Bowhead Whale 158-189 dB
Blue Whale 188 dB (max)
Southern Right Whale 172-187 dB
Gray Whale 185 dB (max)
Source: SURTASS LFA Environmental Impact Statement


This gives a higher SPL for the blue whale, but the highest level for all the whales listed is 190 dB, which is still 33 dB (11 power doublings) below the 223 dB level in question.

--Carl - saying 223 dB is awfully loud :?
http://protask.nl.eu.org/~dennis/emoticons/div34.gif

ya i had trouble believing what i heard, but i trusted him, anyone here watched whale vs squid? HOw loud did they say the whale was?

P.s. ive read the fin and blue whales both reach a max. of 190Db, therefore the loudest of animals...

did anyone see it?????????????? Steve? You were on the show, do u know?
(ok... i think im getting annoying)

Hey!
What is AFO and can we watch it online sometime? That episode sounds of interest.

tv show on discovery channel..in usits moving to animal planet...it shows ppl building mechanical versions of an animal... gather all possible data..then put there stats into a computer and then they are face off in a virtual arena to the finish!

My :twocents: :

That many decibels focused in one "beam" if you will could cause massive internal damage. Given that the Mysticetes have a concavity in the front of their skulls similar to a parabolic dish, doesn't that mean the sonic blast can become a beam of focused sonic energy? Wouldn't that mean they have a lot more control over their sonar than we have over ours?

Sushi and Sake,

John

http://news.nationalgeographic.com/news/20...spermwhale.html