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.

On hot, humid days, you might jump into water to cool down, but for the tiny mangrove rivulus fish, cooling down means jumping out of water, according to a new study from the University of Guelph.

In the study published today in the journal Biology Letters, the researchers describe how these fish air-chill themselves on solid ground in order to drop their body temperatures. The researchers also found that fish exposed to higher temperatures for a week tolerated warmer water better.

The fish jump out of the water to escape rising temperatures, said integrative biology professor Pat Wright, senior author of the study.

As debate roils over EPA regulations proposed this month limiting the release of the potent greenhouse gas methane during fracking operations, a new University of Vermont study funded by the National Science Foundation shows that abandoned oil and gas wells near fracking sites can be conduits for methane escape not currently being measured.

The study, to be published in Water Resources Research on October 20, demonstrates that fractures in surrounding rock produced by the hydraulic fracturing process are able to connect to preexisting, abandoned oil and gas wells, common in fracking areas, which can provide a pathway to the surface for methane.

A recent paper published in the Proceedings of the National Academies of Science showed that methane release measured at abandoned wells near fracking sites can be significant but did not investigate how the process occurs.