The effects of Global warming on fisheries assessed in new study

A report to be published Thursday in the journal Nature suggests that global warming may increase upwelling in several ocean current systems around the world by the end of this century, especially at high latitudes, and will cause major changes in marine biodiversity.Since upwelling of colder, nutrient-rich water is a driving force behind marine productivity, one possibility may be enhancement of some of the world’s most important fisheries.However, solar heating due to greenhouse warming may also increase the persistence of “stratification,” or the horizontal layering of ocean water of different temperatures. The result could be a warm, near-surface layer and a deep, cold layer.

Nitrous Oxide emissions and Ice Ages

Nitrous oxide (N2O) is an important greenhouse gas that doesn’t receive as much notoriety as carbon dioxide or methane, but a new study confirms that atmospheric levels of N2O rose significantly as the Earth came out of the last ice age and addresses the cause.An international team of scientists analyzed air extracted from bubbles enclosed in ancient polar ice from Taylor Glacier in Antarctica, allowing for the reconstruction of the past atmospheric composition. The analysis documented a 30 percent increase in atmospheric nitrous oxide concentrations from 16,000 years ago to 10,000 years ago. This rise in N2O was caused by changes in environmental conditions in the ocean and on land, scientists say, and contributed to the warming at the end of the ice age and the melting of large ice sheets that then existed.

CO2 pulses and the last Ice Age

A new study shows that the rise of atmospheric carbon dioxide that contributed to the end of the last ice age more than 10,000 years ago did not occur gradually, but was characterized by three “pulses” in which C02 rose abruptly.Scientists are not sure what caused these abrupt increases, during which C02 levels rose about 10-15 parts per million – or about 5 percent per episode – over a period of 1-2 centuries. It likely was a combination of factors, they say, including ocean circulation, changing wind patterns, and terrestrial processes.

Methane sink discovered in oceanic rock

Since the first undersea methane seep was discovered 30 years ago, scientists have meticulously analyzed and measured how microbes in the seafloor sediments consume the greenhouse gas methane as part of understanding how the Earth works. The sediment-based microbes form an important methane "sink," preventing much of the chemical from reaching the atmosphere and contributing to greenhouse gas accumulation. As a byproduct of this process, the microbes create a type of rock known as authigenic carbonate, which while interesting to scientists was not thought to be involved in the processing of methane.

What happens to a river when a dam is removed?

A study of the removal of two dams in Oregon suggests that rivers can return surprisingly fast to a condition close to their natural state, both physically and biologically, and that the biological recovery might outpace the physical recovery. The analysis, published by researchers from Oregon State University in the journal PLOS One, examined portions of two rivers – the Calapooia River and Rogue River. It illustrated how rapidly rivers can recover, both from the long-term impact of the dam and from the short-term impact of releasing stored sediment when the dam is removed.

‘Transponders’ from Japan was ashore along US West Coast

Northwest anglers venturing out into the Pacific Ocean in pursuit of salmon and other fish this fall may scoop up something unusual into their nets – instruments released from Japan called "transponders." These floating instruments are about the size of a 2-liter soda bottle and were set in the ocean from different ports off Japan in 2011-12 after the massive Tohoku earthquake and tsunami. Researchers from Tattori University for Environmental Studies in Japan have been collaborating with Oregon State University, Oregon Sea Grant, and the NOAA Marine Debris Program on the project.

If Hops aid cognitive function in mice, maybe beer will do it in humans

Xanthohumol, a type of flavonoid found in hops and beer, has been shown in a new study to improve cognitive function in young mice, but not in older animals. The research was just published in Behavioral Brain Research by scientists from the Linus Pauling Institute and College of Veterinary Medicine at Oregon State University. It’s another step toward understanding, and ultimately reducing the degradation of memory that happens with age in many mammalian species, including humans.

Water quality alerts do not seem to deter some surfers

Nearly three in 10 surfers admit they knowingly surf during health advisories – nearly the same amount that chooses not to surf during periods of elevated bacteria. About 40 percent of surfers said they were unaware if they had ever surfed during an active health advisory. The data can help public officials better warn surfers of potential health risks, said Anna Harding, co-author of the study and professor in OSU's College of Public Health and Human Sciences. "Beach advisories for bacteria are not having their intended effect of dissuading surfers," Harding said. “The lack of awareness about advisories – and willingness to take risks surfing in water that may be contaminated – suggests the need to educate surfers about behaviors that make them vulnerable to illness."

Lyme disease is older than the human race

Lyme disease is a stealthy, often misdiagnosed disease that was only recognized about 40 years ago, but new discoveries of ticks fossilized in amber show that the bacteria which cause it may have been lurking around for 15 million years – long before any humans walked on Earth. The findings were made by researchers from Oregon State University, who studied 15-20 million-year-old amber from the Dominican Republic that offer the oldest fossil evidence ever found of Borrelia, a type of spirochete-like bacteria that to this day causes Lyme disease. They were published in the journal Historical Biology.

New insight on Antarctic Ice Sheet behavior at end of the last ice age

A new study has found that the Antarctic Ice Sheet began melting about 5,000 years earlier than previously thought coming out of the last ice age – and that shrinkage of the vast ice sheet accelerated during eight distinct episodes, causing rapid sea level rise. The international study, funded in part by the National Science Foundation, is particularly important coming on the heels of recent studies that suggest destabilization of part of the West Antarctic Ice Sheet has begun.