Ecosystems

The northern snakehead fish
October 30, 2015 07:42 AM - USGS Newsroom

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.

2015 Antarctic Ozone Hole larger and formed later than previous holes
October 30, 2015 06:17 AM - NASA

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).

Historic Nitrate Levels Still Plague U.S. Rivers
October 29, 2015 06:16 AM - USGS Newsroom

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. 

Declines in marine, large animals disrupt Earth's nutrient cycle
October 26, 2015 09:04 PM - University of Oxford via EurekAlert!

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. 

Oceans need more protected areas
October 26, 2015 07:32 AM - UNIVERSITY OF BRITISH COLUMBIA

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.

Disease-carrying ticks hitchhike into US on migratory birds
October 25, 2015 09:01 PM - Smithsonian Science News

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.

NASA Spots the 'Great Pumpkin'; Get ready to see a Halloween Asteroid!
October 22, 2015 09:31 AM - NASA Jet Propulsion Laboratory

NASA scientists are tracking the upcoming Halloween flyby of asteroid 2015 TB145 with several optical observatories and the radar capabilities of the agency's Deep Space Network at Goldstone, California. The asteroid will fly past Earth at a safe distance slightly farther than the moon's orbit on Oct. 31 at 10:05 a.m. PDT (1:05 p.m. EDT). Scientists are treating the flyby of the estimated 1,300-foot-wide (400-meter) asteroid as a science target of opportunity, allowing instruments on "spacecraft Earth" to scan it during the close pass.

Asteroid 2015 TB145 was discovered on Oct. 10, 2015, by the University of Hawaii's Pan-STARRS-1 (Panoramic Survey Telescope and Rapid Response System) on Haleakala, Maui, part of the NASA-funded Near-Earth Object Observation (NEOO) Program. According to the catalog of near-Earth objects (NEOs) kept by the Minor Planet Center, this is the closest currently known approach by an object this large until asteroid 1999 AN10, at about 2,600 feet (800 meters) in size, approaches at about 1 lunar distance (238,000 miles from Earth) in August 2027.

Ocean Heat Content Reveals Secrets of Fish Migration Behaviors
October 22, 2015 09:24 AM - University of Miami

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.

The fish that cools off by jumping OUT of the water
October 21, 2015 04:18 PM - University of Guelph.

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.

Heavy rain doesn't mean more trees in African savanna
October 20, 2015 09:38 AM - Princeton University

In 2011, satellite images of the African savannas revealed a mystery: these rolling grasslands, with their heavy rainfalls and spells of drought, were home to significantly fewer trees than researchers had expected. Scientists supposed that the ecosystem's high annual precipitation would result in greater tree growth. Yet a 2011 study found that the more instances of heavy rainfall a savanna received, the fewer trees it had.

To this ecological riddle, Princeton University researchers might have finally provided a solution.

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