USGS researchers investigate reciprocal interactions between pathogens and ecosystems, finding parasites can alter predator-prey dynamics and ecosystem balance. They also examine the role of ants in monitoring ecosystem condition and the impact of fire history on alien plant invasion.
A USGS study reveals that the world's most productive forests, which add new growth each year, have lower birth and death rates. However, if these rates suddenly stop or double, tree numbers would halve in just 30 years. The study suggests that environmental changes considered beneficial to forests may bring about unexpected changes.
A recent study found that acid rain can severely degrade forest soils, leading to poor tree growth rates and potentially high mortality rates. The research, conducted near St. Petersburg, Russia, tracked tree growth for the first time with changes in soil from acid rain, highlighting the need for recovery strategies beyond surface waters.
The USGS showcased its expertise in geospatial data sharing and the intersection of earth sciences with national security. The symposium brought together officials from various government agencies and state governments to discuss future coordination across the homeland security enterprise.
A new USGS-led study warns of the limitations and inaccuracies of microbial source tracking methods, which are used to identify sources of contamination. The study found that fewer than 30% of challenge isolates were correctly classified to their source-animal species.
A massive infestation of invasive sea squirt Didemnum has been found on Georges Bank, covering 50% or more of the seabed. The species is threatening commercial fish species and altering seabed communities.
The USGS warns that avian cholera could spread from the Great Salt Lake as eared grebes migrate to wintering areas, where they congregate in dense groups. The disease is highly contagious among bird species and can sweep through wetlands quickly, killing thousands of birds in a single outbreak.
The USGS and NASA have surveyed the islands, providing detailed elevation maps of the 'first line of defense,' which is less than half the average east coast elevation. The maps show that up to 70% of the first line of defense would be inundated by storm surge associated with Categories 1-5 hurricanes.
The USGS Nonindigenous Aquatic Species (NAS) Alert System tracks the spread of invasive aquatic species across the US. The system allows users to report sightings, receive automatic alerts, and search for specific species.
The Florida manatee population is rising in some regions, with annual growth rates of 3.7% and 6.2% in the Northwest and Upper St. Johns River regions, respectively. However, the Atlantic region's estimated growth rate is 1.1%, suggesting a possible decline or stability, while the Southwest region shows a negative growth rate.
Research reveals high levels of toxic contaminants in New England rivers, affecting aquatic life and human health. Streams draining even small amounts of urban land show signs of degradation, while fish from rural areas accumulate higher mercury levels.
A recent USGS review of scientific literature reveals increased reports of disease outbreaks in turtles, corals, mollusks, mammals, and urchins since 1970. However, no significant trends were detected for seagrasses, decapods, or sharks/rays, with even a decrease in disease reports among fish.
A study by USGS researchers associates drought patterns in the US with multi-decade variations in North Pacific and North Atlantic sea surface temperatures. The research found that positive AMO (warm North Atlantic) and negative PDO (cool North Pacific) are linked to large-scale droughts, affecting regional weather patterns.
Researchers have discovered large reservoirs of nitrates in desert subsoils, challenging the concept that nitrogen is tightly retained in soil. This finding has implications for potential groundwater nitrate contamination following climate change or land-use alterations in natural deserts.
Researchers at USGS and international universities reveal that hot vaporized seawater contributes to the formation of new oceanic crust. High-pressure images of lava cavities show molten salt and exotic minerals formed from steam bubbles, challenging previous assumptions about seawater's boiling point at great depths.
The USGS has discovered a vast area of green mineral olivine on Mars, suggesting that the planet's surface has been dry and free from recent water activity. This finding is significant as it implies that the Martian surface has not experienced significant chemical weathering due to liquid water.
A recent study by the USGS found that 20% of homes in Hillsborough, Rockingham, and Strafford counties have arsenic concentrations above 10 micrograms per liter. In some areas, the incidence is as high as 30%. The study highlights the importance of testing private wells for arsenic to protect public health.
Researchers found that common raven populations in the western Mojave Desert have exploded by 1,500 percent, posing a significant threat to young desert tortoises. The study used artificial baits to assess risk of predation and mapped areas with high predation risk, highlighting the importance of safe refuges for tortoises.
The USGS collaborated with Alpha DVD to produce a comprehensive educational DVD about Alaska's glaciers. The DVD covers glacier characteristics, climate history, and ecosystems, providing a detailed introduction to this natural process.
A new study uses tree ring chronologies to identify patterns of multidecadal oscillations in precipitation, linking them to ocean temperature shifts. The research suggests that the Great Plains, Rockies, and Southwest are prone to megadroughts when tropical Pacific and North Atlantic sea surface temperatures align.
Two studies found that invasive species have significantly fewer parasites than their native competitors, allowing them to outcompete and devastatingly impact native ecosystems. This advantage is due to the poor match between parasite hosts in new environments.
A recent study suggests that dissolved organic matter in water absorbs UV-B, protecting 85% of amphibian habitats. The timing of breeding also plays a crucial role, with early breeding reducing UV-B exposure in certain regions.
Forest thinning may improve plant diversity and support animal habitats if done correctly, according to USGS-funded research. The study found that selective thinning of dense young forests can promote the growth of hardwoods, large trees, and old-growth characteristics.
Researchers have made key findings about the San Andreas fault system, predicting major earthquakes within 30 years for certain areas. The study, which analyzed paleoseismic data from 10 sites, suggests that at least 120 miles of the southernmost section of the fault may rupture in a large earthquake of magnitude 7.6 to 7.8.
A 7.9 magnitude earthquake on Alaska's Denali fault system created a 145-mile scar across the landscape, with measurable offsets of up to 22 feet. The earthquake revealed new surface ruptures, clearly developed scarps and cracks where faults pass beneath glaciers.
The GSA 2002 conference discusses the impacts of human activities on natural systems, including droughts, wildfires, and ground-water depletion. Researchers also explore the role of climate change in shaping Earth's history, as seen in sediment cores from the Great Blue Hole.
The USGS will create maps and data to assess aquatic biodiversity in the Great Lakes region, which supports over 30 communities of unique plants and animals. The goal is to protect habitats and preserve species richness through conservation efforts across 49 states.
Researchers found that a recent swarm of earthquakes was triggered by the injection of molten rock into the earth's crust. The study suggests that continuous GPS and seismic data can be used to forecast the rate and distribution of damaging earthquakes, potentially saving lives and property.
USGS scientists Jon Keeley and C.J. Fotheringham argue that natural fire regimes in chaparral ecosystems are not characterized by frequent small fires, but rather by landscape-scale crown fires. They suggest that limited, strategically placed burns are more cost-effective than large-scale prescription burning.
A massive sand delta, over 325 feet thick and nearly 22 miles wide, was found in ancient shorelines of South Florida. This discovery suggests a river system significantly larger than present-day Florida once flowed through the state.
Recent research reveals a mix of natural and human-induced changes in Florida Bay, with a significant increase in the mussel species Brachidontes exustus and a decline in molluscan diversity. Understanding natural variability is crucial to restore ecosystems to their natural state.
The USGS is studying the Chesapeake Bay Impact Structure to understand its influence on groundwater. Scientists are examining the composition, age, and structure of crystalline basement rocks to learn more about the impact event's effects.
The USGS reports that 45 million residents live in hurricane-prone areas, with population growth doubling since the 1960s. Coastal erosion is expected to result in 1,500 homes lost per year, with approximately 87,000 at risk within 60 years.
Researchers examined paleoecological records, archaeological sites, and historical documents to calibrate their understanding of coastal marine ecosystems. They found that human disturbance led to changes in ecosystem structures and functions, with many species becoming ecologically extinct.
Researchers at U.S. Geological Survey and University of Denver have identified a new bird species, the Gunnison sage-grouse, through DNA analysis and genetic research. The study confirms the species' distinctiveness from the Greater sage-grouse and highlights concerns about its low genetic diversity and population decline.
A minor earthquake occurred in the Evansville area with a preliminary magnitude of 3.9, according to the USGS. This region has been identified as having a potential for damaging earthquakes.
A USGS study links agricultural contaminants to declining amphibian populations in California's Sierra Nevada. Pesticides, such as chlorpyrifos and diazinon, were found to suppress enzyme activity in frogs, leading to population declines.
USGS researchers link Mercury levels in Lake Tulane to global climate changes, while also analyzing African dust's role in affecting coral health. Additionally, scientists explore the Chesapeake Bay bolide's crater formation and its structural implications.
Scientists have discovered a wealth of green minerals, including olivine, on the Martian surface, indicating low levels of chemical weathering by water. This suggests that Mars has remained cold and dry for most of its geologic history, contradicting previous theories about a warm, wet past.
The USGS will install a monitoring well in San Jose to track groundwater pressures and assess earthquake hazards. The project aims to improve models for estimating earthquake shaking in the region, enabling better planning and design of structures to reduce damage from future earthquakes.
Thomas A. Steven, a retired USGS research field geologist, received the 7th Annual Dibblee Medal for his outstanding contributions to field geology and geologic mapping. He was recognized for his work on complex volcanic structures, genesis of ore deposits, and landscape evolution.
The USGS is studying the effects of climate change, fire, and carbon dioxide on ecosystems in America's grasslands, deserts, and mountains. Researchers have found that high mortality rates among grassland birds in Colorado may be caused by small mammals invading nests.
The USGS has released the World Petroleum Assessment 2000, revealing a 20% increase in undiscovered oil and a slight decrease in natural gas. Potential additions to reserves from reserve growth are nearly as large as estimated undiscovered resource volumes.
Scientists from various disciplines gather to develop recommendations for restoring Pacific rivers for salmon habitats. The workshop aims to select candidate watersheds and measurements for evaluating restoration success, bringing together expertise in watershed restoration.
Researchers analyzed X-rays of 180 frogs collected at 16 sites in three states, revealing site-specific and time-dependent influences on malformation development. The study suggests that tadpoles received the same developmental insult at the same stage, contributing to the wide geographic occurrence and variety of deformities.
New USGS research shows that frog and toad abundance and species richness are low in urban areas but near normal in agricultural areas. The study also confirms the role of forests as important amphibian habitat, suggesting that habitat quality is crucial for these species.
USGS scientists have linked recent boreal toad deaths in Rocky Mountain National Park to a chytrid fungus. The fungus has been identified as the cause of amphibian die-offs globally and is being studied for its origin, incidence, distribution, and control methods.
A new study from the USGS and Oregon Graduate Institute reveals that up to 9,000 community water wells in 31 states may be contaminated with MTBE due to proximity to leaking underground storage tanks. The EPA has announced plans to phase out MTBE use in gasoline, but it will persist in the environment for at least a decade.
A new population of non-native Asian swamp eels has been found in south Florida, near the eastern border of Everglades National Park. The eels' genetic differences from previously discovered populations suggest a separate introduction and raise concerns about their potential to disrupt native species and food webs.
The USGS is launching a citizen science program to monitor frogs and toads across the United States. Volunteers will collect data on local amphibian populations, helping scientists understand the decline of these species worldwide.