Algae the ”green” alternative for improving water quality

Washington, May 8 (ANI): According to an Agricultural Research Service (ARS) scientist, algae could be put to use right away to remove nitrogen and phosphorus in livestock manure runoff.

That could give resource managers a new eco-friendly option for reducing the level of agricultural pollutants that contaminate water quality in the Chesapeake Bay.

Microbiologist Walter Mulbry works at the ARS Environmental Management and Byproduct Utilization Research Unit in Beltsville, Md., which is located in the Chesapeake Bay watershed. In 2003, Mulbry set up four algal turf scrubber (ATS) raceways outside dairy barns in Beltsville. The shallow 100-foot raceways were covered with nylon netting that created a scaffold where the algae could grow.

For the next three years, from April until December, a submerged water pump at one end of the raceways circulated a mix of fresh water and raw or anaerobically digested dairy manure effluent over the algae. Within two to three weeks after the ATS system was started up every spring, the raceways supported thriving colonies of green filamentous algae.

Algae productivity was highest in the spring and declined during the summer, in part because of higher water temperatures and also because the raceways provided snails and midge larvae ample opportunity to graze on the algae.

Mulbry and his partners harvested wet algae every four to 12 days, dried it, and then analyzed the dried biomass for nitrogen and phosphorus levels. His results indicate that the ATS system recovered 60 to 90 percent of the nitrogen and 70 to 100 percent of the phosphorus from the manure effluents. (ANI)

Biologists assemble most extensive genetic resource for reef-building coral

Washington, May 12 (ANI): A team led by biologists from The University of Texas at Austin, US, has assembled a nearly complete collection of genes for a species of reef-building coral.

The scientists will use the genetic data to understand natural variations in corals from around the world and how they respond, at the genetic level, to rising water temperatures.

“One of the most important questions for coral biologists is whether it will be possible for corals to adapt to the warming oceans,” said Eli Meyer, postdoctoral researcher in the Section of Integrative Biology.

“Answering that question requires a detailed knowledge of the genes that corals use to respond to stress,” Meyer added.

Meyer and Mikhail Matz, assistant professor of integrative biology, developed an improved method for sequencing all of the genes being used by an organism, known as the “transcriptome.”

Those genes, plus other non-expressed genes and DNA, together equal the organism’s entire genome.

Their analysis revealed about 11,000 different genes in the widely studied Pacific coral, Acropora millepora.

Researchers from around the world have already begun to use the data.

They are studying diverse aspects of coral biology such as response to stress, synchronization of mass spawning and relatedness of coral populations across the Pacific.

“I think this will facilitate an explosion in the science of coral adaptation and evolution,” said Matz. “We developed a big boot to kick down a door leading to coral genomics,” he added.

Matz and Meyer say their method can be used to study the genes of any other organism that isn’t yet common to genomic research.

“In about one month’s time, you can now have almost a complete catalog of any organism’s genes,” said Matz. (ANI)

Australia’s killer bushfires have their origins in Indian Ocean

Sydney, March 25 (ANI): Climate experts have uncovered a link between the Indian Ocean Dipole (IOD) and the killer bushfires in Australia.

Found by Dr Wenju Cai and Tim Cowan, of CSIRO’s Marine and Atmospheric Research, the link indicates that a weather pattern centred on the Indian Ocean may provide an early warning system for major bushfires in southern Australia.

According to a report by ABC News, 11 of 16 major bushfires in Victoria since 1950 have been preceded by what is known as a positive IOD event.

Cai said that an unprecedented three consecutive positive IOD events preceded February’s devastating Black Saturday bushfires.

The IOD refers to temperature fluctuations in the east and western Indian Ocean.

In its negative phase, the IOD brings cool water to the ocean west of Australia and warm water to the north, leading to winds that bring rain-bearing air over the continent.

In the positive phase, water temperatures are reversed and less rainfall travels to Australia, particularly to Victoria where the negative IOD provides winter and spring rains.

As part of their research, Cai and Cowan recorded changes in the IOD using Argo floats, robotic devices that measure the subsurface ocean temperature.

They found the IOD was in an “unprecedented” positive state for three consecutive years leading up to 2009.

They said that this preconditioned the environment to the extent that it was almost inevitable the bushfires, which claimed more than 200 lives, would occur.

“If you look at the accumulative soil moisture in Victoria, it’s unprecedented, it’s never been so dry,” said Cai.

The researchers also found an IOD link to the Ash Wednesday bushfires of February 1983, with a positive event reducing rainfall during the winter of 1982.

According to Cai and Cowan, climate change projections show the frequency of positive IOD events will increase in the future.

“Almost all climate models say under climate change we are going to have an Indian Ocean warming pattern,” said Cai.

“That means it has to be manifested in either more frequent positive IOD events or higher intensity positive IODs,” he added. (ANI)

Coral reefs may start dissolving when CO2 doubles

Washington, March 10 (ANI): In a new study, scientists have determined that if carbon dioxide (CO2) reaches double pre-industrial levels, coral reefs can be expected to not just stop growing, but also to begin dissolving all over the world.

The study, by researchers at the Carnegie Institution and the Hebrew University of Jerusalem, points out that the impact on reefs is a consequence of both ocean acidification caused by the absorption of CO2 into seawater and rising water temperatures.

“Globally, each second, we dump over 1000 tons of carbon dioxide into the atmosphere and, each second, about 300 tons of that carbon dioxide is going into the oceans,” said co-author Ken Caldeira of the Carnegie Institution’s Department of Global Ecology.

“We can say with a high degree of certainty that all of this CO2 will make the oceans more acidic,” he added.

The study was designed to determine the impact of this acidification on coral reefs.

The research team used field data from coral reefs to determine the effects of temperature and water chemistry on coral calcification rates.

Armed with this information, they plugged the data into a computer model that calculated global seawater temperature and chemistry at different atmospheric levels of CO2 ranging from the pre-industrial value of 280 ppm (parts per million) to 750 ppm.

Based on the model results for more than 9,000 reef locations, the researchers determined that at the highest concentration studied, 750 ppm, acidification of seawater would reduce calcification rates of three quarters of the world’s reefs to less than 20 percent of pre-industrial rates.

Field studies suggest that at such low rates, coral growth would not be able to keep up with dissolution and other natural as well as manmade destructive processes attacking reefs.

Prospects for reefs are even gloomier when the effects of coral bleaching are included in the model.

Coral bleaching refers to the loss of symbiotic algae that are essential for healthy growth of coral colonies.

According to their model, the researchers calculated that under present conditions, 30 percent of reefs have already undergone bleaching and that at CO2 levels of 560 ppm, the combined effects of acidification and bleaching will reduce the calcification rates of all the world’s reefs by 80 percent or more.

This lowered calcification rate will render all reefs vulnerable to dissolution, without even considering other threats to reefs, such as pollution.

“Our fossil-fueled lifestyle is killing off coral reefs,” said Caldeira. “If we don’t change our ways soon, in the next few decades we will destroy what took millions of years to create,” he added. (ANI)