The current placement of wind energy towers in the central and southern Great Plains may have relatively few negative effects on sandhill cranes wintering in the region, according to a U.S. Geological Survey study published today.Midcontinental sandhill cranes are important to sporting and tourism industries in the Great Plains, an area where wind energy development recently surged. Scientists with the USGS compared crane location data from the winters of 1998-2007 with current wind tower sites in Texas, Oklahoma, Kansas and New Mexico prairies. Findings showed only a seven percent overlap between cranes and towers, and that most towers have been placed in areas not often used by cranes during the winter. 

Researchers have figured out what makes certain chemicals accumulate to toxic levels in aquatic food webs. And, scientists have developed a screening technique to determine which chemicals pose the greatest risk to the environment.According to the study led by the U.S. Geological Survey, two traits were identified that indicate how chemicals can build up and reach toxic levels:  how easily a chemical is broken down or metabolized by an organism and the chemical’s ability to dissolve in water.These traits account for how most chemicals concentrate, or biomagnify, in ever-higher levels as one goes up the food chain from its base to its top predators, such as fish, people, or polar bears. Chemicals that have the ability to biomagnify, such as DDT, can have adverse effects on human and wildlife health and the environment.  

New research can help water managers along the Rio Grande make wise decisions about how to best use the flow of a river vital for drinking water, agriculture and aquatic habitat. These studies also show how conditions from the prolonged drought in the West have affected the Rio Grande watershed.The Rio Grande forms the world’s longest river border between two countries as it flows between Texas and Mexico, where it is known as the Rio Bravo. The river runs through three states in the U.S., beginning in southern Colorado and flowing through New Mexico and Texas before it forms the border with Mexico.Parts of the Rio Grande are designated as wild and scenic, but most of the river is controlled and passes through several dam and reservoir systems during its 1,896 mile journey to the Gulf of Mexico. The river is managed through a complex system of compacts, treaties, and agreements that determine when and how much water is released along the river’s length. 

USGS scientists have detected toxins known as microcystins produced by various forms of algae in 39 percent of the small streams assessed throughout the southeastern United States. Their recent study looked at 75 streams in portions of Alabama, Georgia, North Carolina, South Carolina and Virginia.

Using statistically modeled maps drawn from satellite data and other sources, U.S. Geological Survey scientists have projected that the near-surface permafrost that presently underlies 38 percent of boreal and arctic Alaska would be reduced by 16 to 24 percent by the end of the 21st century under widely accepted climate scenarios. Permafrost declines are more likely in central Alaska than northern Alaska. Northern latitude tundra and boreal forests are experiencing an accelerated warming trend that is greater than in other parts of the world.  This warming trend degrades permafrost, defined as ground that stays below freezing for at least two consecutive years. Some of the adverse impacts of melting permafrost are changing pathways of ground and surface water, interruptions of regional transportation, and the release to the atmosphere of previously stored carbon. 

Soil acidification from acid rain that is harmful to plant and aquatic life has now begun to reverse in forests of the northeastern United States and eastern Canada, according to an American-Canadian collaboration of five institutions led by the U.S. Geological Survey.The new research shows that these changes are strongly linked to acid rain decreases, although some results differ from expected responses.  "Reduced acid rain levels resulting from American and Canadian air-pollution control measures have begun to reverse soil acidification across this broad region," said Gregory Lawrence, a USGS soil and water chemist and lead author.  "Prior to this study, published research on soils indicated that soil acidification was worsening in most areas despite several decades of declining acid rain.  However, those studies relied on data that only extended up to 2004, whereas the data in this study extended up to 2014. "

Genetic data show the grizzly bear population in the Greater Yellowstone Ecosystem has grown since the 1980s with no loss in genetic diversity, according to a report by the Interagency Grizzly Bear Study Team.Results indicate that the effective population size of Yellowstone grizzly bears, or the number of individuals that contribute offspring to the next generation, has increased 4-fold over a 25-year period. This provides evidence that Yellowstone grizzly bears are approaching the effective size necessary for long-term genetic viability.

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.

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. 

Although the Grand Canyon segment of the Colorado River features one of the most remote ecosystems in the United States, it is not immune to exposure from toxic chemicals such as mercury according to newly published research in Environmental Toxicology and Chemistry. The study, led by the U.S. Geological Survey, found that concentrations of mercury and selenium in Colorado River food webs of the Grand Canyon National Park, regularly exceeded risk thresholds for fish and wildlife.