Ocean Acidification as a Hearing Aid for Fish?

[knocker]

Ocean acidification, which occurs as CO₂ is absorbed by the world's oceans, is a source of concern for marine scientists worldwide. Studies on coral, mollusks, and other ocean denizens are helping to paint a picture of what the future might entail for specific species, should carbon emissions continue to increase.

 

In a new study published in Global Change Biology, University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science researchers Sean Bignami, Su Sponaugle, and Robert Cowen are the first to study the effects of acidification on the larvae of cobia (Rachycentron canandum). Cobia are large tropical fish that spawn in pelagic waters, highly mobile as they mature, and a popular species among recreational anglers.

 

 

http://www.sciencedaily.com/releases/2013/04/130419080012.htm

Edited April 20, 2013 by knocker

[DAVID SNOW]

http://www.sciencedaily.com/releases/2013/04/130419080012.htm

Codswallop.

[laserguy]

Codswallop.

 

Ye-  sounds fishy to me too, or someone's codding, no plaice for that kinda thing etc.

[Methuselah]

Ye-  sounds fishy to me too, or someone's codding, no plaice for that kinda thing etc.

Do you ever change your tuna, barrie? How about Bob Marlin & the Whalers?

[knocker]

Codswallop.

 

I never cease to be amazed at the quality of scientific argument in the forum and the atempts at humour.

Edited April 20, 2013 by knocker

[DAVID SNOW]

I never cease to be amazed at the quality of scientific argument in the forum and the atempts at humour.

Thank You.

[laserguy]

I never cease to be amazed at the quality of scientific argument in the forum and the atempts at humour.

 

I never cease to be amazed at the lengths folk will go to in order to villify CO2 as the 'warming' slant slowly but surely dies a death. Whatever it takes to get the job done,huh?

[BornFromTheVoid]

I never cease to be amazed at the lengths folk will go to in order to villify CO2 as the 'warming' slant slowly but surely dies a death. Whatever it takes to get the job done,huh?

 

So you don't think ocean acidification is real either?

[DAVID SNOW]

So you don't think ocean acidification is real either?

So the PH level of our oceans and seas must be a lot lower now than say,30 years ago?

[BornFromTheVoid]

So the PH level of our oceans and seas must be a lot lower now than say,30 years ago?

 

Depends what you consider "a lot".

[knocker]

Ocean acidification rate may be unprecedented, study says Few parallels in 300-million-year geologic record

The world's oceans may be turning acidic faster today from human carbon emissions than they did during four major extinctions in the last 300 million years, when natural pulses of carbon sent global temperatures soaring, says a new study in Science. The study is the first of its kind to survey the geologic record for evidence of ocean acidification over this vast time period.

 

"What we're doing today really stands out," said lead author Bärbel Hönisch, a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory. "We know that life during past ocean acidification events was not wiped out—new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon."

 

The oceans act like a sponge to draw down excess carbon dioxide from the air; the gas reacts with seawater to form carbonic acid, which over time is neutralized by fossil carbonate shells on the seafloor. But if CO₂ goes into the oceans too quickly, it can deplete the carbonate ions that corals, mollusks and some plankton need for reef and shell-building.

 

That is what is happening now. In a review of hundreds of paleoceanographic studies, a team of researchers from five countries found evidence for only one period in the last 300 million years when the oceans changed even remotely as fast as today: the Paleocene-Eocene Thermal Maximum, or PETM, some 56 million years ago. In the early 1990s, scientists extracting sediments from the seafloor off Antarctica found a layer of mud from this period wedged between thick deposits of white plankton fossils. In a span of about 5,000 years, they estimated, a mysterious surge of carbon doubled atmospheric concentrations, pushed average global temperatures up by about 6 degrees C, and dramatically changed the ecological landscape.

 

The result: carbonate plankton shells littering the seafloor dissolved, leaving the brown layer of mud. As many as half of all species of benthic foraminifers, a group of single-celled organisms that live at the ocean bottom, went extinct, suggesting that organisms higher in the food chain may have also disappeared, said study co-author Ellen Thomas, a paleoceanographer at Yale University who was on that pivotal Antarctic cruise. "It's really unusual that you lose more than 5 to 10 percent of species over less than 20,000 years," she said. "It's usually on the order of a few percent over a million years." During this time, scientists estimate, ocean pH—a measure of acidity--may have fallen as much as 0.45 units. (As pH falls, acidity rises.)

 

In the last hundred years, atmospheric CO₂ has risen about 30 percent, to 393 parts per million, and ocean pH has fallen by 0.1 unit, to 8.1--an acidification rate at least 10 times faster than 56 million years ago, says Hönisch. The Intergovernmental Panel on Climate Change predicts that pH may fall another 0.3 units by the end of the century, to 7.8, raising the possibility that we may soon see ocean changes similar to those observed during the PETM.

 

 

http://www.eurekalert.org/pub_releases/2012-03/teia-oar022912.php

[4wd]

It's fallen from 8.2 to 8.1, scary stuff.
 

[knocker]

The pH of sea water varies over a surprisingly narrow range so a drop of o.1 in this time frame is significant. As was pointed out in the paper above. For an insight into The Marine Carbonate System which is quite complex  I would recommend, "Oceanography" by Summerhayes and Thorpe.

[laserguy]

So you don't think ocean acidification is real either?

 

Obviously not as pH8.1 is still profoundly alkaline. You wouldn't believe the hassle I have in getting my beer wort to a  healthily acidic ph5.2 ( the yeast love that). When the oceans' pH goes below 7 I'll accept that it has been most certainly 'acidified'. I'm not overly concerned anyway so long as I can still get cod 'n' chips of a Friday evening. Mind you, I guess the blighters will be harder to catch if it improves their hearing; they'll hear the trawlers coming from miles away....

[knocker]

Interesting you compare your beer making with the Marine Carbonate System. Have you tried mine waste water? Some of that's down to a pH of 3.0.

[BornFromTheVoid]

I'm not overly concerned anyway so long as I can still get cod 'n' chips of a Friday evening.

 

I get the feeling that this is the basis of all your scientific opinions...

[knocker]

Obviously not as pH8.1 is still profoundly alkaline.

 

Regarding alkalinity It is important to remember the definition of alkalinity in sea water as the concentration of hydrogen carbonate and carbonate ions. It is not a measure of the pH or how alkaline sea water is. Once this is recognised, it is easy to appreciate that sea water alkalinity and acidity change in the same direction:

 

But of course you knew that.

Edited April 21, 2013 by knocker

[Methuselah]

Obviously not as pH8.1 is still profoundly alkaline. You wouldn't believe the hassle I have in getting my beer wort to a  healthily acidic ph5.2 ( the yeast love that). When the oceans' pH goes below 7 I'll accept that it has been most certainly 'acidified'. I'm not overly concerned anyway so long as I can still get cod 'n' chips of a Friday evening. Mind you, I guess the blighters will be harder to catch if it improves their hearing; they'll hear the trawlers coming from miles away....

Are you a pelagic fish, barrie? How do you know that a pH decrease of 0.1 is harmless to a marine animal's physiology?

[knocker]

I never cease to be amazed at the lengths folk will go to in order to villify CO2 as the 'warming' slant slowly but surely dies a death. Whatever it takes to get the job done,huh?

 

I know it's so annoying and this isn't quite up to date.

 

Source Summerhayes and Thorpe.

[laserguy]

I get the feeling that this is the basis of all your scientific opinions...

 

I just knew this was coming... yawn. Cod goes well with very low pH I find - it's a little bland without vinegar.  Ye - I did know that, knocks. Did you know that to reduce the pH of my beer to 5.2 I have to add calcium sulphate, which is actually alkaline? Took a while to get my head around that back in the day but it all makes sense now!

Edited April 22, 2013 by laserguy

[laserguy]

Are you a pelagic fish, barrie? How do you know that a pH decrease of 0.1 is harmless to a marine animal's physiology?

 

Nope - fish,pelagic or otherwise,can't type. And how do you know that a pH decrease would be harmful? They'll live, I'm sure.

Edited April 22, 2013 by laserguy

[Methuselah]

Nope - fish,pelagic or otherwise,can't type. And how do you know that a pH decrease would be harmful? They'll live, I'm sure.

I don't know, barrie; and I've never said that I do...

[BornFromTheVoid]

Nope - fish,pelagic or otherwise,can't type. And how do you know that a pH decrease would be harmful? They'll live, I'm sure.

 

 

Extensive dissolution of live pteropods in the Southern Ocean

A link to the google scholar search for "ocean acidification" http://scholar.google.com/scholar?hl=en&q=ocean+acidification&btnG=&as_sdt=1%2C5&as_sdtp=

[laserguy]

I don't know, barrie; and I've never said that I do...

 Nope, but you implied it by raising the question in the first place. Neat trick. Yes BFTV - yada yada etc, but will my cod be alright? That is the question...

[knocker]

I find it difficult to understand why your trolling is allowed LG when the rest of us get censured. Well I do actually...................

Edited April 23, 2013 by knocker