Archive for the ‘University of Bristol’ Category

<> on June 9, 2010 in Houma, Louisiana.

By Susannah Cullinane, CNN

The world’s oceans have become 26% more acidic since the start of the Industrial Revolution and continue to acidify at an “unprecedented rate,” threatening marine ecosystems, aquaculture and the societies that rely on them, scientists say.

In a report released Thursday, researchers say that carbon dioxide emissions from human activities such as fossil fuel burning are the primary cause of ocean acidification.

They say the rate of change may be faster than at any time in the last 300 million years, predicting that by 2100 there will have been a 170% increase in ocean acidity, compared to pre-industrial times.

The report is based on the findings from a September 2012 Symposium on the Ocean, at which 540 experts from 37 countries discussed research on ocean acidification, and has been updated with more recent research.

Unless carbon dioxide emissions are reduced, marine ecosystems will be damaged and the impact of climate change will be worsened, the scientists warn. “The only known realistic mitigation option on a global scale is to limit future atmospheric CO2 levels.”

The report says oceans currently act as a CO2 “sinkhole” absorbing approximately a quarter of emissions.

“As ocean acidity increases, its capacity to absorb CO2 from the atmosphere decreases. This decreases the ocean’s role in moderating climate change,” they write.

The increased acidity will also change the ocean environment, with evidence suggesting that some organisms will be less able to survive, while others, such as seagrass, may thrive.

Acidification is faster in Arctic waters because cold water is richer in CO2, while melting sea ice worsens the problem, they say.

“Within decades, large parts of the polar oceans will become corrosive to the unprotected shells of calcareous marine organisms,” the report says, while in the tropics the growth of coral reefs may be hampered.

“People who rely on the ocean’s ecosystem services are especially vulnerable and may need to adapt or cope with ocean acidification impacts within decades,” it says. “Tropical coral reef loss will affect tourism, food security and shoreline protection for many of the world’s poorest people.”

“Very aggressive reductions in CO2 emissions are required to maintain a majority of tropical coral reefs in waters favorable for growth,” the report says.

One of the report’s authors is Daniela Schmidt, from the University of Bristol, in the UK.

Schmidt said the research highlighted the impact acidification would have on biodiversity and aquaculture and the societies that rely on them for their food and economic well-being.

“We’re talking about countries that strongly depend on this, in warmer countries where there are complex problems with climate change as it is,” Schmidt said.

“What I’m hoping is that people realize that CO2 is not just a question of global warming. That we are acidifying the ocean at a rate that has been unprecedented — for millions and millions of years,” she said.

“The more CO2 emissions, the more acidification,” Schmidt said. “The ocean is in direct interchange with the atmosphere.”

If acidification continued to increase at its current rate, “you will definitely see damage,” she said. “The first signs we can already see today, in oyster farms off the West Coast of the United States.”

Schmidt said while 90% of the world’s ocean was in equilibrium with the atmosphere, some oyster hatcheries in this area were located in the 10% that wasn’t.

Oysters in the larval stage were much more vulnerable to damage, she said. “When (more acidic) water comes up and hits the hatchery, they close the whole thing.”

While tanks could be closed off to more acidic seawater, Schmidt said that by 2100 the issue would be there every day. “So we can’t just switch off that tap anymore.”

She said the report would be presented in Warsaw, Poland, on November 18, during the U.N. Conference of the Parties climate change meeting.

Schmidt said while she hoped the research would lead to stricter emissions limits, “the realist in me thinks that we’ve been discussing this for decades. This isn’t a problem that is just going to go away. It’s simple. The consequences are frightening.”

The 2012 symposium that led to the report was sponsored by the Scientific Committee on Oceanic Research, the Intergovernmental Oceanographic Commission of UNESCO, and the International Geosphere-Biosphere Programme.

http://www.cnn.com/2013/11/14/world/ocean-acidification-report/index.html?hpt=hp_t3

hydrogen-from-urine-for-cars

British scientists said they have harnessed the power of urine and are able to charge a mobile phone with enough electricity to send texts and surf the Internet.

Researchers from the University of Bristol and Bristol Robotics Laboratory in south west England said they had created a fuel cell that uses bacteria to break down urine to generate electricity, in a study published in the Royal Society of Chemistry journal Physical Chemistry Chemical Physics.

“No one has harnessed power from urine to do this so it’s an exciting discovery,” said engineer Ioannis Ieropoulos Tuesday.

“The beauty of this fuel source is that we are not relying on the erratic nature of the wind or the sun; we are actually reusing waste to create energy.

“One product that we can be sure of an unending supply is our own urine,” he added.

The team grew bacteria on carbon fibre anodes and placed them inside ceramic cylinders.

The bacteria broke down chemicals in urine passed through the cylinders, building up a small amount of electrical charge which was stored on a capacitor.

Ieropoulos hoped that the cell, which is currently the size of a car battery, could be developed for many applications.

“Our aim is to have something that can be carried around easily,” he explained.

“So far the microbial fuel power stack (MFC) that we have developed generates enough power to enable SMS messaging, web browsing and to make a brief phone call.

“The concept has been tested and it works – it’s now for us to develop and refine the process so that we can develop MFCs to fully charge a battery.”

They hope the technology will eventually be used to power domestic devices.

Read more: http://www.foxnews.com/world/2013/07/17/scientists-power-mobile-phone-using-urine/#ixzz2ZJII394D

_65983396_bombus_terrestris_1

Bumblebees (Bombus terrestris) can detect flowers’ electric fields, scientists have discovered. Results indicate floral electric fields improve the bees’ ability to discriminate between different flowers. When used with visual signals, electrical cues can enhance the bee’s memory of floral rewards. Researchers suggest this method of signalling provides rapid and dynamic communication between plants and pollinators.

The findings are published in the online journal Science Express.

Flowering plants reward pollinators with nectar and pollen in return for their assistance in the flowers’ sexual reproduction. Flowers attract pollinators using cues such as bright colours, patterns and enticing fragrances but this study suggests the importance of electrostatic information as an additional cue for the first time.

“Of course it has existed for a long time but this is a new way we can look at the interactions between bees and flowers,” said Prof Daniel Robert of the University of Bristol. “This doesn’t throw away any of the previous work on cues that flowers are using, it adds another layer on top of that.” Prof Robert and his team were studying the mechanism of pollen transfer between flowers via an insect pollinator.

“What the pollen needs to ‘know’ is when to ‘jump’ onto the ‘vehicle’ – the bee – and when to get off it. So it’s a selective adhesion type of question,” Prof Robert told BBC Nature.

The team’s investigation highlighted the possible importance of electrostatic forces. “We looked at [existing] literature and realised that the bees were being positively charged when they fly around, and that flowers have a negative potential. “There’s always this electrical bias around. As a sensory biologist, suddenly I thought: can the bees sense that?” Prof Robert said.

Dominic Clarke, one of the lead authors, designed “fake” electric flowers in a laboratory “flying arena” to prove that electric fields are important floral cues. Electric flowers with a positive charge offered a sucrose reward while those without offered a bitter quinine solution. Bumblebees were allowed 50 visits in the flying arena and the last 10 visits showed the bees had learnt to tell the difference between the flowers.

When the electric field was turned off, “the bee goes back to selecting at random because it hasn’t got a way to tell the difference between them any more,” commented Mr Clarke. “That’s how we know it was the electric field that they were learning.”

“Animals are just constantly surprising us as to how good their senses are. More and more we’re starting to see that nature’s senses are almost as good as they could possibly be,” Mr Clarke told BBC Nature. Prof Robert summed up: “We know they can detect these electrostatic fields… this is the tip of the iceberg, there’s so much more that we haven’t seen yet.”

http://www.bbc.co.uk/nature/21508035

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.