Annual snow accumulation on West Antarctica’s coastal ice sheet increased dramatically during the 20th century, according to a new study published today (Wednesday 4 November) in the American Geophysical Union journal Geophysical Research Letters. The last three decades saw more snow build up on the ice sheet than at any other time in the last 300 years.

The research gives scientists new insight into Antarctica’s ice sheet. Understanding how the ice sheet grows and shrinks over time enhances scientists’ understanding of the processes that impact global sea levels.

The new study used ice cores to estimate annual snow accumulation from 1712 to 2010 along the coastal West Antarctic. Until 1899, annual snow accumulation remained steady, averaging 33 and 40 centimeters (13 and 16 inches) water, or melted snow, each year at two locations.

As a result of increasing atmospheric carbon dioxide concentrations, the chemistry of the Southern Ocean is expected to change so fast over the next few decades that tiny creatures at the base of the food web may soon struggle to form their shells. New research by scientists from UH Mānoa and the University of Alaska, Fairbanks (UAF) finds that, for some organisms, the onset of such critical conditions will be so abrupt, and the duration of events so long, that adaption may become impossible.

The study, published this week in the journal Nature Climate Change, uses a number of Earth System Models to explore how the uptake of anthropogenic carbon dioxide and the resulting ocean acidification will affect the Southern Ocean over the next century. 

The invasive northern snakehead fish found in the mid-Atlantic area is now cause for more concern, potentially bringing diseases into the region that may spread to native fish and wildlife, according to a team of U.S. Geological Survey scientists.

The team found that a group of adult northern snakehead collected from Virginia waters of the Potomac River south of Washington D.C. were infected with a species of Mycobacterium, a type of bacteria known to cause chronic disease among a wide range of animals.

"Mycobacterial infections are not unusual among fish, but they are nonetheless noteworthy because they can have an impact at the population level and potentially even affect other fish and wildlife," said lead author Christine Densmore, a veterinarian with the USGS.

The 2015 Antarctic ozone hole area was larger and formed later than in recent years, said scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA).

During 1945 to 1980, nitrate levels in large U.S. rivers increased up to fivefold in intensively managed agricultural areas of the Midwest, according to a new U.S. Geological Survey study. In recent decades, nitrate changes have been smaller and levels have remained high in most of the rivers studied. 

A new study reveals that in the past large land animals, whales, seabirds and fish played a vital role in recycling nutrients from the ocean depths, spreading them far and wide across the globe and taking them deep inland. However, the paper says massive declines in their populations coupled with the extinction of most of Earth's large mammals have disrupted this efficient system of recycling important nutrients, particularly phosphorous. The researchers calculate that the ability of whales and terrestrial megafauna to transport nutrients around the globe has been reduced to just 6% of their global capacity before mass extinctions and population declines. 

Despite global efforts to increase the area of the ocean that is protected, only four per cent of it lies within marine protected areas (MPAs), according to a University of British Columbia study.

UBC Institute for Ocean and Fisheries researchers found that major swaths of the ocean must still be protected to reach even the most basic global targets.

In 2010, representatives from nearly 200 countries met in Nagoya, Japan, and adopted the United Nations' Aichi Targets, in a bid to stem the rapid loss of biodiversity. The countries committed to protecting at least 10 per cent of the ocean by 2020.

Researchers who examined thousands of migratory birds arriving in the United States from Central and South America have determined that three percent carry ticks species not normally present in the United States. Some of the birds, they say, carry disease-causing Ricksettia ticks.

When the plague swept through Europe in 1665, no one could figure out how the devastating disease spread. But after a tailor in the small village of Eyam in central England died that September, people eventually put two and two together. He had received a parcel of cloth infested with fleas just 4 days before dying of bubonic plague. Within a month, five other villagers had succumbed, and the local vicar convinced the town to voluntarily put itself under quarantine. It eventually became clear that it was fleas, probably on rats, that spread the plague so far and so quickly.

But now it appears that the plague did not always infect fleas—and the disease may not have always spread so rapidly or been as devastating. A new study of ancient DNA from the teeth of 101 Bronze Age skeletons has found that seven people living 2800 to 5000 years ago in Europe and Asia were infected with Yersinia pestis, the bacteria that causes the plague. 

Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science developed a new method to estimate fish movements using ocean heat content images, a dataset commonly used in hurricane intensity forecasting. With Atlantic tarpon as the messenger, this is the first study to quantitatively show that large migratory fishes, such as yellowfin and bluefin tunas, blue and white marlin, and sailfish have affinities for ocean fronts and eddies.