THE Oceans and Seas Thread (merged)

Cid_Yama · **Posted:** Mon Aug 25, 2008 5:59 am

Rising ocean acidity slows marine fertilisation

Rising acidification of the ocean could reduce fertilisation of marine invertebrates and might eventually wipe out colonies of sea urchins, lobsters, mussels and oysters, according to a study.

Scientists knew that ocean acidification was eating away at the shells of marine animals, but the new study has found that rising acidity hindered marine sperm from swimming to and fertilising eggs in the ocean.

"We were completely surprised because people had been looking at the effect of acidification on calcified structures of marine animals, but there was no evidence to suggest it was affecting non-calcified structures, like a sperm or an egg," she said.

The study of sea urchins around southeast Australia found a link between increased ocean acidity and a reduction in swimming speed and motility of sea urchin sperm.

The researchers measured sperm swimming speed, sperm motility, fertilisation success and larval developmental success in sea urchins in normal seawater with a pH 8.1 and also in water with a pH 7.7.

The experiment found that in water with acidity at 7.7, the sperm swam much more slowly and began failing to meet the eggs.

Fertilisation fell by 25 per cent and in almost 26 per cent of cases where eggs were fertilised, they did not survive to develop into larvae, said the study published in Current Biology.

"It is widely believed that seawater is chemically well-buffered, but these results show that the acidification process already well under way may threaten the viability of many marine species," Prof. Williamson said.

She said acidity levels of 7.7 were already occurring in patches of ocean off the west coast of the US.

"What we have now is evidence that the world's marine life is far more sensitive to ocean acidification than first suspected, and that means our oceans may be very different places in the not-too-distant future," Prof. Williamson said.

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Cid_Yama · **Posted:** Fri Sep 05, 2008 7:41 am

"Because it is difficult to detect, unlike mass coral bleaching, we don't know whether we have reached or surpassed the critical thresholds for any coral species, such as we have for temperature thresholds," Salm said.

Not only is ocean acidification hard to detect, he warned, ocean acidification is potentially irreversible.

In July, scientists at the International Coral Reef Symposium in Florida declared acidification as the largest and most significant threat that oceans face today. Current estimates show that all coral reefs could be gone by the end of the century or, in the worst case scenario, possibly decades sooner, Salm pointed out.

"Coral reefs are the lifeblood of our oceans and we depend on them for survival," said Suzanne Case, executive director of The Nature Conservancy of Hawaii. "Without urgent action to limit carbon dioxide emissions and improve management of marine protected areas, even vast treasured reefs like the Great Barrier Reef and Northwestern Hawaiian Islands will become wastelands of dead coral."
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mos6507 · **Posted:** Fri Sep 05, 2008 12:11 pm

joewp wrote:

About the only thing we could do now is just stop messing with the oceans.

How do you do that with a population of 6.7 billion?

arkwriter · **Joined:** Thu Jul 17, 2008 12:00 am **Posts:** 2

the chain of life has been broken, nay smashed, by the relentless expansion of the human population and our dependance on plastic.
The mind boggles as to how we managed to get into such dire straits, or of how we can possibly change things for the better. It is also strange to read messages from those who ridicule, or are so ignorant, of global warming, but I suppose that, when we are all utterly doomed, it is probably the best to remain ignorant and enjoy life whilst one can.

Cid_Yama · **Posted:** Sat Sep 27, 2008 10:54 pm

‘Desertification’ of the East China Sea

The East China Sea is one of the largest “ocean deserts” in the world. Marine lives cannot exist there for lack of oxygen. When the oxygen level in sea water decreases to three milligrams per liter, most stocks of fish and shellfish will either leave or die of suffocation.

According to www.caijing.net.cn, China’s Finance and Economics website, as early as October 2006, a United Nations Environmental Program (UNEP) Report placed the estuaries of the Yangtze River and the Pearl River on the list of additional “ocean deserts.”

In 2005, the then China General Administration for Environmental Protection started an analysis on the Yangtze River estuary and adjacent waters and land areas. Included were eight river cities in Jiangsu Province, six coastal cities in Zhejiang Province, Shanghai, and waters off the Yangtze estuary and the Hangzhou Bay. In all, the study covered a land area of 41,440 square miles and a water area of 15,200 square miles.

The samples collected from the sea floors revealed that one third of the explored water area had no meiofauna, or small invertebrates that live at the sea bottom, indicating a serious “desertification” of the ocean floors.
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doodlebug2 · **Joined:** Sun May 25, 2008 12:00 am **Posts:** 57

Besides dying , how about full of crap.
After a storm this past week blew through here (Coastal VA)
the beach was littered with plastic crap. Bottles, cans, bags, cig filters, wrapers, you name it. Tons of it. Just think of this stuff in the worlds oceans, it is sad and shameful. Plus, humans will be long gone and it will still be floating around. yuck

Cid_Yama · **Posted:** Tue Oct 07, 2008 9:46 pm

Seas turn to acid as they soak up CO2

The Bay of Naples is renowned for its breathtaking beauty and glittering clear waters. For centuries, tourists have flocked to the region to experience its glories.

But beneath the waves, scientists have uncovered an alarming secret. They have found streams of gas bubbling up from the seabed around the island of Ischia. 'The waters are like a Jacuzzi - there is so much carbon dioxide fizzing up from the seabed,' said Dr Jason Hall-Spencer, of Plymouth University. 'Millions of litres of gas bubble up every day.'

The gas streams have turned Ischia's waters into acid, and this has had a major impact on sea life and aquatic plants. Now marine biologists fear that the world's seas could follow suit.
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Cid_Yama · **Posted:** Fri Oct 10, 2008 9:31 pm

Ocean seeding making waves

The topic of "ocean seeding" has been making waves among delegates.

Could "polluting" the marine environment restrain rising temperatures and rising carbon dioxide concentrations in the atmosphere?

According to Margaret Leinen, chief scientist of the company Climos, it could; and the magic pollutant is iron filings.

Placed in the oceans, the theory goes that they will stimulate the growth of phytoplankton, tiny marine plants, which will then photosynthesise more CO2 out of the atmosphere and down into the water column.

The idea has been around for a long time and studies date back at least a decade, without having given us a definitive answer to whether it will work.

At a seminar here on ocean geoengineering, as the approach is known, Ms Leinen told us of her company's plans to seed trial sites of ocean hundreds of kilometres across, and - under the auspices of independent scientists - conduct studies that would satisfy academics, regulators and investors.

Scientifically, the issue is not whether the mechanism works - it does - but what else happens afterwards.

How deep will the carbon be carried, through physical or biological paths? How long will it stay stored? Will the plants' decay produce methane or nitrous oxide, more potent greenhouse gases than CO2?

Investors will want to know simply whether it can turn a profit - which hangs on whether it is shown to work, and so whether it qualifies for carbon credits.

Greenpeace scientist David Santillo expressed the concerns of many.

When money is involved, how can we guarantee independent science?

http://news.bbc.co.uk/2/hi/science/nature/7654721.stm

My main concern is that it will add to ocean acidification and anoxia. This could just as easily kill the oceans and I'm not seeing anywhere where this issue is even being considered.

billg · **Posted:** Sun Nov 30, 2008 8:33 am

Quote:

Ocean Acidification: Worse Than the Big Problem We Thought It Was
Posted on Nov. 25, 2008

Ocean acidification is happening at 10 to 20 times the rate predicted by existing climate models, according to an eight-year study. The rapid acidification of the oceans is linked to global warming and may be a sign that the oceans, the largest absorber of atmospheric carbon dioxide, may not be as hardy as presumed. The changes threaten disaster for marine life with shells that are easily corroded by acid. Marine biologist Nancy Knowlton said, “This is typical of so many climate studies—almost without exception things are turning out to be worse than we originally thought.” [National Geographic News].

The study was done around Takoosh Island off the coast of Washington state and represents the first detailed dataset on variations of coastal pH at a temperate latitude, where the world’s most productive fisheries are found [Times of India]. The researchers took over 24,000 measurements of ocean pH over an 8-year period. During that time, the pH of the seawater was predicted to decrease by only 0.015 points. Instead, the data showed that seawater pH dropped by 0.36 to about 8.1. “The increase in acidity we saw during our study was about the same magnitude as we expect over the course of the next century,” said study co-author Timothy Wootton [National Geographic News].

The researchers found that atmospheric carbon dioxide exhibited a corresponding steady change, with current levels as high as they’ve ever been in the last 650,000 years. About one-third of man-made carbon dioxide is dissolved into the oceans and removed from the atmosphere. But once in seawater, carbon dioxide forms carbonic acid, lowering seawater pH. “Declines in seawater pH were expected to happen very slowly, so we’ve been lax in dealing with the problem, but our study shows ocean acidification may be happening much quicker,” said Wootton [The Guardian].

The study noted a significant decline in large mussels, which normally dominate their niches but have calcium carbonate shells that are weakened or corroded by acid. According to computer models of the local marine life, the rise in acidity is likely to cause substantial falls in the numbers of mussels and large goose barnacles, while algae and populations of smaller barnacles may increase [The Guardian]. The changing balance in the ecosystem may be felt throughout the food chain and may speed up as it goes along, as large populations of certain species begin to die off.

Last year, the Intergovernmental Panel on Climate Change predicted that rising ocean temperatures and acidification would cause the extinction of many coral species by the end of the century. The new study, published in the Proceedings of the National Academy of Sciences [subscription required], paints an even grimmer picture. The researchers would like to collect more data to determine if the situation around Takoosh Island is representative of a global pattern. “It’s been thought pH in the open oceans is well buffered, so it’s surprising to see these fluctuations,” [Wootton] said [BBC News].

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dissident · **Joined:** Sat Apr 08, 2006 12:00 am **Posts:** 710

Apparently our understanding of ocean chemical mixing is quite poor. This is rather strange since the heat transport is captured quite well by high resolution ocean models. There must be some process that delays the mixdown of carbonic acid from the surface layers to the deeper ones.

Pretorian · **Posted:** Sun Nov 30, 2008 10:31 am

M_B_S wrote:

Drive to a fish and ship shop with your lovely SUV? :twisted:

Yes 1 billion people need the daily fish to survive... Have a nice day driving your SUV

Ever thought that that 1 000 000 000 people are actually killing the ocean much more than any other billion? They should be good to go, not much to miss here.

PS And I do enjoy driving my SUV, thank you

Tanada · **Posted:** Sat Feb 21, 2009 6:09 am

alokin · **Joined:** Fri Aug 24, 2007 12:00 am **Posts:** 1213

I found this in science daily: [url=http://www.sciencedaily.com/releases/2009/03/090303193950.htmScience Daily[/url]
It's quite rare that nobody thought of this what#s so obvious before. Like every gardener searches the biggest plants to save the seeds!

neocone · **Joined:** Sat Sep 23, 2006 12:00 am **Posts:** 307

Sadly the Oceans only are 1% as efficient as land in producing food and proteins... this is how everywhere you look now the fishing stocks are close to complete collapse and fisherman are glorified welfare recipients who pretend to work some weeks of the year.

Soon to be joined by auto workers but I digress...

vtsnowedin · **Joined:** Fri Jul 11, 2008 12:00 am **Posts:** 1394

When oil gets to $200/bl the fish catch will not pay for the fuel and the trawlers will stay tied up at the dock. Then the recovery period will begin. In the meantime end such stupid practices as requiring all by-catch to be thrown overboard. Once netted and brought to the surface fish are dead or soon will be and throwing them over board is a waste we can no longer afford.

THE Oceans and Seas Thread (merged)

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