USGS Newsroom

3-D Mapping of Isaac Water Levels

OC_Web@usgs.gov (Office of Communications and Publishing) — Sat, 1 Sep 2012 11:34:38 EDT

3-D Mapping of Isaac Water Levels

A new technology is being deployed by U.S. Geological Survey scientists this weekend to map urban flooding caused by Hurricane Isaac. Called “terrestrial lidar,” or “T-lidar”, this new capability will enable scientists to collect highly detailed information in select population areas in Louisiana, Mississippi, and Alabama where the hurricane had the greatest impact.

The portable instrument allows scientists to quickly generate 3-D maps of buildings, dams, levees and other structures, and can show areas of storm damage as well. In a four-to-five minute scan, the instrument collects millions of topographic data points in a full 360-degree view to quickly produce highly accurate topographic information and can map areas up to two-thirds of a mile away.

The information gathered from this pilot project will be used by USGS to develop 3-D models of streets and structures, including the levels floodwaters reached, as well as current water levels in the form an interactive 3-D flood inundation map. The map will help identify where the potential threat of future floodwaters is greatest, and will help determine the extent of wind and flood damages caused by Isaac.

"If a picture paints a thousands words, a T-lidar scan paints several million words to capture the fleeting aftermath of a hurricane's impact," said USGS Director Marcia McNutt. "The ability to rapidly preserve for posterity a quantifiable, three-dimension representation of storm damage is going to open the doors for new flood hazard science."

T-lidar looks sideways from ground level, enabling it to capture vertical details, such as water levels, that airborne lidar cannot. This enables it to capture the extent of flooding. The USGS will be using both a tripod mounted and a truck-mounted version. While the tripod version takes individual scans from multiple locations that later have to be combined to develop its 3-D maps, the truck-mounted version is continuously collecting information that is available almost immediately.

"Using terrestrial lidar in this fashion has the possibility of helping us quickly assess high-water marks, current water levels, and to some degree flood damage, in a very short time," said Athena Clark, director of the USGS Alabama Water Science Center. "We’re always looking for better, more efficient and cost effective ways of advancing the science and this technology has some great possibilities."

"Lidar" stands for "light detection and ranging." Where "radar" uses radio waves as a form of measurement, "lidar" uses light. Terrestrial lidar, sometimes called “terrestrial laser scanning,” uses a sensor that emits laser pulses and measures distance by how long it takes the reflected laser beam to "bounce back" to the instrument. TLS can provide very precise data, to millimeter accuracy, to enable scientists to build high-resolution 3-D models of objects.

"We are collecting storm-tide information that will allow scientists to study the impacts of the storm in three dimensions," said Toby Minear, a research hydrologist at the USGS California Water Science Center, who is participating in the study. "Imagine a 360-degree panoramic photo, but made with laser points where everything you can see has a known elevation and location. These 'point clouds' can be put together to create a full 3-D map of an area containing many millions of data points."

In addition to the use of terrestrial lidar, the USGS is also planning airborne lidar flights to assess the level of coastal change caused by Isaac along the Gulf Coast. More information on both these studies will be released when they are completed.

Media Advisory: Measuring the Impact of Isaac

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 30 Aug 2012 10:45:21 EDT

Media are invited to join U.S. Geological Survey crews working in areas impacted by Isaac as they retrieve storm-tide sensors deployed prior to the storm, measure high-water marks, make inland flood measurements, and collect water samples to measure water quality following the storm.

The storm-tide sensors will be retrieved from Mobile Bay in Alabama to Breton Sound in Louisiana, including Lake Pontchartrain. The sensors were installed to measure the storm-tide height and intensity of Hurricane Isaac. The information will help define the depth and duration of the storm-tide, as well as the time of its arrival and retreat. That information will help assess storm damage, discern between wind and flood damage, and improve computer models used to forecast future floods.

As Isaac moves inland, flooding from the drenching rains becomes an issue, and as the storm progresses northward, additional measurements will be required in the Midwest states.

What: Reporters can accompany the USGS crews as they retrieve the storm-tide sensors, measure high water marks, and collect water samples from various locations along the Gulf Coast. USGS crews will also be making flood measurements at affected streamgages inland from the coast that are critical for accurate flood forecasts.

Points of Contact:

• Louisiana:	George Arcement	(225) 978-4203
• Mississippi	Michael Plunkett	(601) 933-2940
• Alabama:	Athena Clark	(334) 395-4141

When/Where: The specific schedules and locations will vary by state depending on flooding and road closures. Contact the state point of contact for more information.

Additional information on USGS activities before, during and after the storm can be found on the USGS website.

USGS Storm-Surge Sensors Deployed Ahead of Isaac

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 28 Aug 2012 17:59:21 EDT

Hurricane response crews from the U.S. Geological Survey are installing more than 120 storm-tide sensors at key locations along the Gulf Coast from the Florida Panhandle to Louisiana in advance of the arrival of Hurricane Isaac.

The storm-tide sensors, frequently called storm-surge sensors, will be secured to piers and poles in areas where the hurricane is expected to make landfall. The instruments being installed will record the precise time the storm-tide arrived, how ocean and inland water levels changed during the storm, the depth of the storm-tide throughout the event, and how long it took for the water to recede.

"While every hurricane brings the possibility for devastation, it also brings a learning opportunity by capturing valuable scientific data that improves our understanding of the pattern and timing of storm-driven coastal inundation," said USGS Director Marcia McNutt. "This vital information will help reduce loss of life and property now and in future events."

Storm-tides are increases in ocean water levels generated at sea by extreme storms and can have devastating coastal impacts. In locations where tidal forecasts are known, the sensors being installed can also help determine storm surge. For differences between storm-surge and tidal-surge, visit the National Hurricane Center's website.

This information will be used to assess storm damage, discern between wind and flood damage, and improve computer models used to forecast future coastal inundation.

In addition, rapid deployment gauges will be installed along critical roadways to provide real-time information to forecast floods and coordinate flood-response activities in the affected areas. The sensors augment a network of existing U.S. Geological Survey gauging stations already in place before the storm arrives.

Of the sensors deployed, 12 of those have real-time capability that will allow viewing of the storm-tide as Hurricane Isaac approaches and makes landfall. The real-time gauges have water level, precipitation and wind sensors that will transmit all data hourly. All gauge data can be found at the USGS Storm-Tide Mapper.

Providing information to support future forecasts could ultimately save lives during future storms. These sensors were deployed for the first time during Hurricane Rita in 2005. Before then, scientists had limited data available to study the effects of storm surge.

"Forecasters at the National Weather Service rely on USGS real-time and long-term data for input into its predictive models that are used to improve storm surge models and prepare storm-tide warnings," said Brian McCallum, assistant director of the USGS Georgia Water Science Center. "Floodplain managers, federal, state and local emergency preparedness officials, emergency responders, scientists and researchers all benefit from the storm-tide and associated flood data. It’s useful for flood damage prevention and public safety."

The USGS studies the impacts of hurricanes and tropical storms to better understand potential impacts on coastal areas. Information provided through the sensor networks provides critical data for more accurate modeling and prediction capabilities and allows for improved structure designs and response for public safety.

The USGS also continuously monitors water levels and flows at thousands of the nation's streams on a real-time basis. The public can access this information for their area at the USGS Current Streamflow Conditions web page. Also, USGS WaterAlert allows users to receive a text or email from the USGS when waters are rising in rivers and streams near them.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov

Isaac Expected to Change Sandy Coasts from Louisiana to Florida

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 28 Aug 2012 16:58:32 EDT

Sandy beaches and barrier islands along the northern Gulf of Mexico are highly vulnerable to beach and dune erosion as Hurricane Isaac makes landfall this week, according to a new U.S. Geological Survey assessment. The projections also show which coastal areas may see storm-surge topping sand dunes and beaches.

Probabilities for coastal change have been calculated for parts of the Louisiana, Mississippi, and Alabama coastlines and for the Florida Panhandle.

On Saturday, the USGS released an assessment of expected coastal change in Florida, but the change in the storm’s path has reduced the concern for erosion of west central Florida beaches, shifting focus primarily to sandy beaches and barrier islands from Florida’s Panhandle to Louisiana.

Beaches and dunes can serve as a first line of defense for residents on coasts exposed to these types of storms. During tropical storms and hurricanes, elevated water levels and waves can lead to dramatic coastal change. According to the latest USGS research, during even the weakest hurricanes, wave height and storm surge combine to increase water levels along the Gulf Coast shoreline by 14 and a half feet higher than their normal levels.

"We can now combine more accurate coastal data with powerful new scientific models to provide the very best predictions of hurricane surge, waves, and erosion," said USGS Director Marcia McNutt. "USGS scientists used the latest NOAA forecasts to ensure that the people of the Gulf Coast are not surprised by the impacts of Isaac."

Using a USGS-developed model, scientists incorporated measurements of beach elevation and wave and surge forecasts from the National Oceanic and Atmospheric Administration to determine the probabilities of collision, overwash and inundation during the coming storm.

Collision is when waves attack the base of dunes and cause dune-front erosion. Overwash occurs when waves and storm surge overtop dunes and transport sand landward. Inundation, the most extreme of the three, occurs when increased water levels completely submerge beaches and dunes.

"Earlier this year, USGS released a report detailing hurricane induced erosion hazards for category 1-5 storms. The predictions released this week are based on the same methods, but tailored to waves and storm surge specific to Hurricane Isaac," said Hilary Stockdon, USGS research oceanographer. "As the storm moves across the Gulf, we use real-time storm and wave forecasts from NOAA to determine where beach erosion and inundation are most likely to occur."

These predictions, available on the USGS Hurricanes and Extreme Storms website, show the probable impacts of Isaac at each location along the coast. This assessment may be updated if there are significant changes in the storm’s projected track or strength. Based on the current assessment, the percentages of each type of coastal change were estimated for each of the following states:

Louisiana

Beach and dune erosion is very likely for 66 percent of Louisiana's sandy beaches
29 percent of the sandy beaches in this area are very likely to experience overwash.
18 percent of the Louisiana's barrier islands are expected to be inundated; however, the majority of this inundation will occur only on Louisiana's Chandeleur Islands.
100 percent of the Chandeleur Islands are very likely to experience overwash and 83 percent of these islands are very likely to be inundated. This beach system was devastated during Hurricane Katrina, making it more vulnerable to-low intensity storms.

Mississippi

Beach and dune erosion is very likely for 89 percent of Mississippi's sandy beaches and barrier islands.
20 percent of the sandy beaches are very likely to experience overwash.
Inundation of the beach system is not expected.

Alabama

Beach and dune erosion is very likely for 52 percent of Alabama's sandy beaches and barrier islands.
11 percent of the sandy beaches are very likely to experience overwash.
3 percent of the sandy beaches are very likely to be inundated

Florida Panhandle

Beach and dune erosion is very likely for 32 percent of the Panhandle's sandy beaches
2 percent of the sandy beaches are very likely to experience overwash.
Inundation of the beach system is not expected.

After the worst of the storm passes, USGS may send teams to the field to measure the impact of Hurricane Isaac on the coastline.

Aerial photography and elevation surveys of post-storm beach conditions are used to document the impacts of hurricane waves and currents on the beach. Information obtained from the surveys allows scientists to discern the degree of changes to beaches and coastal environments and determine how much the land has eroded and where new inlets have cut through. The newly acquired data will also be used to make more accurate predictive models of future coastal impacts from severe storms and identify areas vulnerable to extreme coastal change.

The areal photos can visually demonstrate the severe impacts of hurricane surge on beaches. This photo shows the effects that hurricane waves and surge have had on Dauphin Island, Alabama from 2004 -2008.

In May, the USGS released a report assessing probability of coastal change for the Gulf Coast when facing hurricanes of different strengths. The report included an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov

Florida Beaches and Dunes Face Erosion Risk During TS Isaac

OC_Web@usgs.gov (Office of Communications and Publishing) — Sat, 25 Aug 2012 14:30:00 EDT

USGS Calculates Likelihood of Coastal Changes

ST. PETERSBURG, Fla. – Seventy-eight percent of Florida's west central coast and 23 percent of the Panhandle are very likely to face beach and dune erosion as Tropical Storm Isaac moves into the area early next week, according to an assessment released by the U.S. Geological Survey on Friday. These numbers are likely to increase if the storm reaches hurricane strength as predicted.

For many Florida beaches that had significant erosion during Tropical Storm Debby in June, the impact of additional erosion may be even more significant.

"With Isaac bearing down on Florida beaches so soon on the heels of Debby, this is like a 'one-two punch' for the dunes that provide coastal protection," said USGS Director Marcia McNutt. "As these sand dunes dynamically morph to new configurations, our science-based models can help in forecasting where communities are at most risk from storm damage in this ever-changing spatial and temporal pattern of storm intensity and coastal morphology."

During tropical storms and hurricanes, elevated water levels and waves can lead to dramatic coastal change through erosion of beaches and dunes. These beaches and dunes can serve as a first line of defense for residents for many coasts exposed to these types of storms.

Using a USGS-developed model scientists incorporated measurements of beach elevation and wave and surge forecasts from the National Oceanic and Atmospheric Administration to determine the probabilities of collision, overwash and inundation during the coming storm.

"Tropical Storm Debby eroded many beaches along Florida's west central coast, impacting the property of many gulf-side residents and hotels," said Hilary Stockdon, a USGS oceanographer and lead of the assessment team. "Beaches typically take years to recover from severe storm impact, so having what is likely to be a Category 1 or 2 hurricane move up the coast just two months later could take a heavy toll on some already heavily eroded areas."

In addition to the likelihood of erosion, the team found that 15 percent of the west central coast was very likely to face overwash should the storm make direct landfall there, while that likelihood was only 5 percent for the Panhandle where dune elevations are higher. Unless forecasts change significantly, inundation is not expected in either area.

The team will revise its calculations as storm track and intensity forecasts are updated, and will update their projections and website accordingly. They plan to include the Alabama and Mississippi coasts in their assessments this weekend. Additional information on coastal change and extreme storms can be found on the USGS Coastal Change Hazards website.

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events such as this one in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property.

For the latest forecasts on the storm, listen to NOAA radio. For information on preparing for the storm, visit Ready.gov or Listo.gov.

Gulf Coast Vulnerable to Extreme Erosion in Category 1 Hurricanes: New Model to Help Community Planners, Emergency Managers

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 30 May 2012 8:30:00 EDT

Seventy percent of the Gulf of Mexico shoreline is vulnerable to extreme erosion during even the weakest hurricanes, according to a new report by the U.S. Geological Survey released just prior to the start of the 2012 hurricane season.

USGS scientists used state-of-the-art modeling to determine the probabilities of erosion, overwash and inundation during direct hurricane landfall for sandy beaches along the entire U.S. Gulf Coast shoreline.

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property. The report also includes an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.

"The Gulf Coast's beaches provide abundant recreational opportunities, contribute substantially to the local economy, and demand the highest real estate values," said USGS Director Marcia McNutt. "This important research raises awareness on the specific nature of the vulnerability of these beautiful beaches to impacts from even Cat-1 hurricanes so that property damage can be minimized through proper planning."

In a storm, high waves and storm surge can act together to erode beaches and inundate low-lying lands; during hurricane landfall, these changes can sometimes be catastrophic.

"Beaches along the Gulf of Mexico are extremely vulnerable to erosion during hurricanes, in part, because of low elevations along the coast," said Hilary Stockdon, a USGS research oceanographer and lead author of the study. "For example, the average elevation of sand dunes on the west coast of Florida is eight feet. On Florida’s Atlantic coast, the average is 15 feet."

During the landfall of a category-1 storm, where winds are between 75 and 94 miles per hour, overwash is very likely for 70 percent of Gulf Coast beaches. Overwash occurs when waves and storm surge overtop dunes and transport sand landward. Overwash is likely at these locations because of increased water levels at the shoreline. During category-1 hurricane events on the Gulf Coast, wave height and storm surge combine to increase water levels at the shoreline by 14 and a half feet higher than their normal levels.

"People continue to build communities in coastal areas that shift and move with each passing storm," said Stockdon. "This model helps us predict the potential impact of future storms and allows us to identify where the most vulnerable areas are located along the coast."

Additional findings from the report show that during a category-1 storm landfall, 27 percent of sandy beaches along the U.S. Gulf of Mexico are projected to be inundated, which occurs when increased water levels completely submerge beaches and dunes. If category-5 storms occur, where winds are 157 miles per hour or higher, 89 percent of these beaches are likely to be inundated during a direct landfall.

USGS scientists used methodology developed from a decade of USGS research on storm-driven coastal change hazards as the basis for these calculations. Observational data were combined with sophisticated hydrodynamic modeling to predict the coastal changes provided in the report. As new data and storm predictions become available, the report's analysis will be updated to describe how coastal vulnerability may change in the future.

Key findings and the full report are available online.

A similar report detailing erosion hazards along the east coast is planned later this year. This report will provide an assessment of vulnerability for east coast barrier island communities.

A Big Day for Science: Citizens Have Contributed One Million Observations to Top Nature Database

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 3 May 2012 9:00:00 EDT

RESTON, Va. — Thanks to citizen-scientists around the country, the USA National Phenology Network hit a major milestone this week by reaching its one millionth nature observation.

The millionth observation was done by Lucille Tower, a citizen-scientist in Portland, Ore., who entered a record about seeing maple vines flowering. Her data, like all of the entries, came in through USA-NPN’s online observation program, Nature's Notebook, which engages more than 4,000 volunteers across the country to observe and record phenology – the timing of the recurring life events of plants and animals such as when cherry trees or lilacs blossom, when robins build their nests, when salmon swim upstream to spawn or when leaves turn colors in the fall.

Each record not only represents a single data point — the status of a specific life stage of an individual plant or animal on one day – but also benefits both science and society by helping researchers understand how plants and animals are responding to climate change and, in turn, how those responses are affecting people and ecological systems.

"My dream is that through the wonders of modern technology and the National Phenology Network we could turn the more than six billion people on the planet into components of our scientific observing system," said USGS Director Marcia McNutt. "We could make giant leaps in science education, improve the spatial and temporal coverage of the planet, lower the cost of scientific data collection, and all while making ordinary citizens feel a part of the scientific process."

Jake Weltzin, a U.S. Geological Survey scientist and the executive director of USA-NPN, concurs. "Hitting the one millionth observation is exciting because researchers and decision-makers need more information to understand and respond to our rapidly changing planet. More information means better-informed decisions that ensure the continued vitality of our natural areas that we all depend on and enjoy."

For example, said Weltzin, the data in Nature's Notebook are already being used to benefit society, including the development of more accurate indicators of spring, forecasting the onset of allergy seasons or the chances of western wildfires, managing wildlife and invasive plants, and setting goals for habitat restoration. Ultimately, such information can be used for better managing water resources, wildlife and ecosystem management, and even help farmers and ranchers across the nation.

Changes in phenology are among the most sensitive biological indicators of global change. Across the world, many springtime events are occurring earlier — and fall events happening later — than in the past. These changes are happening quickly for some species and more slowly, or not at all, for others, altering relationships and processes that have been dynamically stable for thousands of years. Some wildlife —like caribou and butterflies — are becoming mismatched from their plant food resources, which are responding differently. Migrations for some birds are changing too, as they can now overwinter instead of moving south for the winter, or as they fly north more quickly to keep pace with an advancing front of spring flowering.

Because of this, said Weltzin, scientists need more and better information about the pace and pattern of nature — locally to nationally — to answer important scientific and societal questions, and to build the tools and models needed to help people understand and adapt to the changes.

"So much of our improved understanding about global environmental changes is driven by varied and valuable sources of information that include networks of citizen-scientists," said John Wingfield, National Science Foundation’s assistant director for biological sciences. "The public at large has played an important role collecting observations and data for a hundred years and more. Knowledge and data gained from their work will continue to have a lasting effect on how we understand regularly recurring biological phenomena for hundreds of plant and animal species and contribute to the policy arena."

Gwen Lundburg in Seattle is one citizen-scientist who has contributed hundreds of entries into Nature’s Notebook. "Just noticing small changes like tiny purple lilac buds suddenly turning green has taught me to look more closely at my plants," Lundburg said. "I see things in my garden I never saw before."

With the help of citizen-scientist volunteers, working in concert with professionals, the USA-NPN, which was established in 2007, collects, stores and freely shares phenological data on more than 800 species of plants and animals. The Nature’s Notebook observing program has been in operation since 2009. The coordinating office of the organization is located at 1955 E. 6^th St., Tucson, Ariz., 85721. For more information, visit the USA National Phenology Network, or contact Jake Weltzin at 520-626-3821 or jweltzin@usgs.gov.

Rise in Asian Tiger Shrimp Sightings Prompts Scientific Look at Invasion Concerns

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 26 Apr 2012 11:00:00 EDT

Additional Contact: Keeley Belva, NOAA 301-713-3066 Keeley.Belva@noaa.gov

Content updated - 4/26/2012 6:48 pm

GAINESVILLE, Fla. – The recent rise in sightings of non-native Asian tiger shrimp off the U.S. Atlantic and Gulf of Mexico coasts has government scientists working to determine the cause of the increase and the possible consequences for native fish and seafood in those waters.

Researchers from the U.S. Geological Survey and National Oceanic and Atmospheric Administration are working with state agencies from North Carolina to Texas to look into how this transplanted species from Indo-Pacific, Asian and Australian waters reached U.S. waters, and what the increase in sightings means for native species.

"We can confirm there was nearly a tenfold jump in reports of Asian tiger shrimp in 2011," explained Pam Fuller, the USGS biologist who runs the agency's Nonindigenous Aquatic Species database. "And they are probably even more prevalent than reports suggest, because the more fisherman and other locals become accustomed to seeing them, the less likely they are to report them."

NOAA scientists are launching a research effort to understand more about the biology of these shrimp and how they may affect the ecology of native fisheries and coastal ecosystems. As with all non-native species, there are concerns over the potential for novel avenues of disease transmission and competition with native shrimp stocks, especially given the high growth rates and spawning rates compared with other species.

"The Asian tiger shrimp represents yet another potential marine invader capable of altering fragile marine ecosystems," said NOAA marine ecologist James Morris. "Our efforts will include assessments of the biology and ecology of this non-native species and attempts to predict impacts to economically and ecologically important species of the Atlantic and Gulf of Mexico."

The cause of the rapid increase in sightings remains uncertain, Fuller added. The non-native shrimp species may have escaped from aquaculture facilities, although there are no longer any known Asian tiger shrimp farms presently in operation in the United States. It may have been transported in ballast water from ships or possibly arrived on ocean currents from wild populations in the Caribbean or other locations.

Fuller's team at USGS has been tracking reports of Asian tiger shrimp since they first came to the attention of marine scientists and resource managers in 1988, when nearly 300 of them were collected off the coasts of South Carolina, Georgia and Florida within three months. Scientists tracked the cause back to an isolated incident that accidentally caused an estimated 2,000 animals to be released from an aquaculture facility operating at that time in South Carolina.

It was not until 18 years later that reports of the non-native shrimp resurfaced. In 2006, a commercial shrimp fisherman caught a single adult male in Mississippi Sound near Dauphin Island, Ala. Within months, additional specimens were noted in North Carolina’s Pamlico Sound, Louisiana’s Vermilion Bay and other parts of Florida and the Carolinas. The species was later reported off the coasts of Georgia, Mississippi and Texas in 2008, 2009 and 2011, respectively.

Scientists have not yet officially deemed the Asian tiger shrimp "established" in U.S. waters, and no one is certain what triggered the recent round of sightings. With so many alternative theories about where these shrimp are coming from and only a handful of juveniles reported, it is hard for scientists to conclude whether they are breeding or simply being carried in by currents.

To look for answers, USGS and NOAA scientists are examining shrimp collected from the Gulf and Atlantic coasts to look for subtle differences in their DNA, information that could offer valuable clues to their origins. This is the first look at the genetics of wild caught Asian tiger shrimp populations found in this part of the U.S., and may shed light on whether there are multiple sources.

"We're going to start by searching for subtle differences in the DNA of Asian tiger shrimp found here – outside their native range –to see if we can learn more about how they got here," said USGS geneticist Margaret Hunter, "If we find differences, the next step will be to fine-tune the analysis to determine whether they are breeding here, have multiple populations, or are carried in from outside areas."

Anyone who sees one or more shrimp suspected to be an Asian tiger shrimp is asked to note the location and report the sighting to the USGS NAS database. If possible, freeze a specimen to help confirm the identity and contribute to a tissue repository maintained by NOAA.

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Satellite Tracking Reveals Sea Turtle Feeding Hotspots

OC_Web@usgs.gov (Office of Communications and Publishing) — Wed, 1 Feb 2012 15:00:00 EDT

Study Offers Clues to Loggerheads' Elusive Habits at Sea

GAINESVILLE, Fla. – Satellite tracking of threatened loggerhead sea turtles has revealed two previously unknown feeding ‘hotspots’ in the Gulf of Mexico that are providing important habitat for at least three separate populations of the turtles, according to a study published recently in the journal Biological Conservation.

The two sites, located in the open waters off the coast of Southwest Florida and the northern tip of the Yucatan Peninsula, were found by a team of scientists when they compiled and analyzed loggerhead tracking data.

The researchers' goal was to synthesize tracking data from three genetically distinct loggerhead populations to learn more about how they use the Gulf of Mexico. By identifying the specific location of regularly used habitat, the results provide invaluable information for marine planning and management for this species, whose populations in the Gulf of Mexico are well below historic levels and in recent years have continued to decline drastically in some areas.

The maritime feeding grounds also hold the first clues about how loggerhead sea turtles spend time at sea – which is, in essence, most of their lives.

"Up until now, management actions that affect loggerheads have often focused on their limited time at nesting beaches, or on fisheries regulations," said Kristen Hart, Ph.D., the U.S. Geological Survey research ecologist who led the synthesis. "Our findings open up important new options for marine habitat conservation, and provide valuable geographic data that can be used to strategically locate marine reserves based on the best available science, as called for in the new National Ocean Policy."

"The use of satellite tags for tracking marine animals has opened our eyes to the secret lives of some of nature's most elusive creatures," said USGS director Marcia McNutt, "At first a scientific tool to understand the life cycle of animals, such as white sharks and leatherback turtles, who rarely come into contact with humans, these tags may now be the main hope for understanding what we can do, or what we should stop doing, in order to bring them back from the road to extinction."

Researchers intercepted female loggerheads after their nesting forays to beaches and outfitted them with satellite tags at study sites in the Florida Panhandle, Casey Key in southwest Florida, and Dry Tortugas National Park. They then tracked the females’ migrations and used a new method to determine precisely when they had arrived at "hotspot" foraging areas, in two geographically different locations.

Seven female turtles migrated to foraging sites off Southwest Florida, while the other three took up residence at foraging sites at the Yucatan site. Once the researchers applied the new method for synthesizing their satellite-tracking data, it became clear that these loggerhead turtles from all three populations consistently converged around two common sites. This confirmed a hunch that the researchers had developed after years of tracking turtles.

At both of the feeding hotspots, turtles selected individual sites where they foraged in shallow or nearshore waters less than fifty meters deep. Turtles appeared to prefer their own distinct territories, where they tended to remain resident. This suggests that it may be possible to accurately predict where sea turtles will feed, information that will prove vital for managers looking to focus conservation efforts on prime foraging habitat.

Researchers don't yet know what attracts loggerheads from around the Gulf to these specific feeding areas, although generally, loggerheads forage on the bottom of the sea floor for crustaceans such as crabs, lobsters, clams or conchs.

"The logical next step is to investigate what makes these particular sites 'prime' foraging grounds by mapping and sampling the habitat types found on the sea floor," explained Hart. "It would also be useful to tag loggerheads at these foraging sites to confirm how long they reside in these areas, or alternatively to see where they go next."

Severe Declines in Everglades Mammals Linked to Pythons

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 30 Jan 2012 14:52:18 EDT

Additional Partnerships:


State Museum of Pennsylvania	Denison University

Constrictor Snakes (B-roll): Video footage (B-roll) of Everglades National Park biologists hunting and capturing a Burmese Python in Florida.

Editors: For frequently asked questions about this study and Burmese pythons, please visit the Fort Collins Science Center, Giant Constrictor Snakes in Florida website.

HOMESTEAD, Fla. -- Precipitous declines in formerly common mammals in Everglades National Park have been linked to the presence of invasive Burmese pythons, according to a study published today in the Proceedings of the National Academy of Sciences.

The study, the first to document the ecological impacts of this invasive species, strongly supports that animal communities in this 1.5-million-acre park have been markedly altered by the introduction of pythons within 11 years of their establishment as an invasive species. Mid-sized mammals are the most dramatically affected.

Bobcats are one of the predators that may be negatively affected by pythons, which both compete with them for prey and prey on them. Photo copyrighted by Christopher Gillette, Florida International University. This photo may be used by media and others in association with the Burmese pythons and Everglades press release. (High resolution image)

Once-common opossums are now rarely seen in Everglades National Park, likely because of being preyed upon by Burmese pythons. Photo copyrighted by Christopher Gillette, Florida International University. This photo may be used by media and others in association with the Burmese pythons and Everglades press release. (High resolution image)

The most severe declines, including a nearly complete disappearance of raccoons, rabbits and opossums, have occurred in the remote southernmost regions of the park, where pythons have been established the longest. In this area, populations of raccoons dropped 99.3 percent, opossums 98.9 percent and bobcats 87.5 percent. Marsh and cottontail rabbits, as well as foxes, were not seen at all.

"Pythons are wreaking havoc on one of America's most beautiful, treasured and naturally bountiful ecosystems," said U.S. Geological Survey Director Marcia McNutt. "Right now, the only hope to halt further python invasion into new areas is swift, decisive and deliberate human action."

The researchers collected their information via repeated systematic night-time road surveys within the park, counting both live and road-killed animals. Over the period of the study, researchers traveled a total of nearly 39,000 miles from 2003 to 2011 and compared their findings with similar surveys conducted in 1996 and 1997 along the same roadways before pythons were recognized as established in Everglades National Park.

The scientists who authored the paper noted that the timing and geographic patterns of the documented mammal declines are consistent with the timing and geographic spread of pythons.

The authors also conducted surveys in ecologically similar areas north of the park where pythons have not yet been discovered. In those areas, mammal abundances were similar to those in the park before pythons proliferated. At sites where pythons have only recently been documented, however, mammal populations were reduced, though not to the dramatic extent observed within the park where pythons are well established.

"The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park and justifies the argument for more intensive investigation into their ecological effects, as well as the development of effective control methods," said Michael Dorcas, lead author of the study, a professor at Davidson College in North Carolina, and author of the book Invasive Pythons in the United States. "Such severe declines in easily seen mammals bode poorly for the many species of conservation concern that are more difficult to sample but that may also be vulnerable to python predation."

The mammals that have declined most significantly have been regularly found in the stomachs of Burmese pythons removed from Everglades National Park and elsewhere in Florida. The authors noted that raccoons and opossums often forage for food near the water's edge, a habitat frequented by pythons in search of prey.

The authors suggested that one reason for such dramatic declines in such a short time is that these prey species are “naïve” – that is, they not used to being preyed upon by pythons since such large snakes have not existed in the eastern United States for millions of years. Burmese pythons over 16 feet long have been found in the Everglades. In addition, some of the declining species could be both victims of being eaten by pythons and of having to compete with pythons for food.

"It took 30 years for the brown treesnake to be implicated in the nearly complete disappearance of mammals and birds on Guam; it has apparently taken only 11 years since pythons were recognized as being established in the Everglades for researchers to implicate pythons in the same kind of severe mammal declines," said Robert Reed, a USGS scientist and co-author of the paper. "It is possible that other mammal species, including at-risk ones, have declined as well because of python predation, but at this time, the status of those species is unknown."

The scientists noted that in their native range in Asia, pythons have been documented to consume leopards. Consequently, even large animals, including top predators, are susceptible to python predation. For example, pythons have been documented consuming full-grown deer and alligators. Likewise, the authors state that birds, including highly secretive birds such as rails, make up about a fourth of the diet of Everglades pythons, and declines in these species could be occurring without managers realizing it.

"Our research adds to the increasing evidence that predators, whether native or exotic, exert major influence on the structure of animal communities," said John Willson, a study co-author, a research scientist at Virginia Tech University and author of the book Invasive Pythons in the United States. "The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the national park boundaries, are likely profound, but are probably complex and difficult to predict. Studies examining such effects are sorely needed to more fully understand the impacts pythons are having on one of our most unique and valued national parks."

The authors found little support for alternative explanations for the mammal declines, such as disease or changes in habitat structure or water management regimes.

"This severe decline in mammals is of significant concern to the overall health of the Park's large and complex ecosystem," said Everglades National Park superintendent Dan Kimball. "We will continue to enhance our efforts to control and manage the non-native python and to better understand the impacts on the Park. No incidents involving visitor safety and pythons have occurred in the Park. Encounters with pythons are very rare; that said visitors should be vigilant and report all python sightings to park rangers," Kimball said.

On Jan. 23, 2012, the U.S. Fish and Wildlife Service published a rule in the Federal Register that will ban the importation and interstate transportation of four non-native constrictor snakes (Burmese python, northern and southern African pythons, and the yellow anaconda) that threaten the Everglades and other sensitive ecosystems. These snakes are being listed as injurious species under the Lacey Act. In addition, the FWS will continue to consider listing as injurious five other species of nonnative snakes: the reticulated python, boa constrictor, DeSchauensee’s anaconda, green anaconda and Beni anaconda.

The paper, Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park, was published online on Jan. 30, 2012, in the Proceedings of the National Academy of Sciences. The authors are Michael E. Dorcas, Davidson College; John D. Willson, Virginia Tech University; Robert N. Reed, USGS; Ray W. Snow, NPS; Michael R. Rochford, University of Florida; Melissa A. Miller, Auburn University; Walter E. Meshaka, Jr., State Museum of Pennsylvania; Paul T. Andreadis, Denison University; Frank J. Mazzotti, University of Florida; Christina M. Romagosa, Auburn University; and Kristen M. Hart, USGS.

Groundwater Storage Losses Substantial Across Eight State Aquifer System

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 1 Dec 2011 13:10:46 EDT

More than 280 million acre-feet of groundwater has been withdrawn from the Mississippi embayment aquifer system between 1870-2007, according to a new water modeling tool developed by the U.S. Geological Survey.

This cumulative withdrawal, which is the equivalent of five feet of water over 78,000 square miles, contributes to one of the largest losses of groundwater storage anywhere in the United States.

The new USGS modeling tool was designed to help resource managers find a balance between water supply and demand for future economic and environmental uses. The three-dimensional model provides a holistic picture of how water flows below ground and how it relates to surface-water. The Mississippi embayment aquifer system encompasses approximately 78,000 square miles in Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri and Tennessee. A report documenting past and current groundwater conditions, and tools to forecast regional response to human use, climate variability, and land-use changes are all available online.

"Our groundwater aquifers are nature's own natural method for storing water safely long term where it is less vulnerable to loss through evaporation and surface contamination," explained USGS director Marcia McNutt. "We should be as concerned about loss of groundwater as we are about dropping levels in reservoirs behind dams, because in the depths of the worst drought, when the rivers run dry, it is only the groundwater that will sustain us."

"This model can assist water resource managers faced with increasing management challenges and constraints," said USGS hydrologist, Brian Clark. "This model could be used to evaluate regional issues, such as streamflow declines from groundwater pumping or conservation scenarios to lessen water level declines."

The Mississippi embayment aquifer system includes one of the nation’s most productive agricultural regions, with an annual value of $3 billion per year. Two of the region’s most important aquifers lie beneath the Mississippi embayment. The pumping from the Mississippi River Valley alluvial aquifer accounts for more than 12 percent of all groundwater pumped in the United States.

"This model will help officials find ways to better manage the area's present and future groundwater resources," said USGS Arkansas Water Science Center Director, Dave Freiwald. "This is the most recent large-scale, comprehensive assessment of groundwater resources in the area."

This report is a product of a four-year study being funded by the USGS Groundwater Resources Program. Information derived from this and future studies of more than 30 regional aquifers will provide a collective assessment of America's groundwater availability.

To develop the model, scientists examined more than 2,600 geophysical logs, some dating back to the early 1960’s. Researchers examined groundwater and surface-water data from the early 1900’s to 2007, groundwater withdrawal information, and thousands of miles of surface-water bodies to illustrate how the water system works and how supplies have changed.

A comprehensive report detailing the research, “Groundwater Availability of the Mississippi Embayment,” and a factsheet, “A New Tool to Assess Groundwater Resources in the Mississippi Embayment,” are available online.

Map showing the Mississippi embayment aquifer system area. (Larger image)

Study Identifies Probable Cause of Capital City Plume

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 12 Sep 2011 11:00:00 EDT

MONTGOMERY, Ala. – Disposal of industrial wastewater by the commercial printing industry into sumps, floor drains and sinks that drained into sewer and stormwater systems is the probable cause of widespread groundwater contamination in downtown Montgomery, according to a U.S. Geological Survey report released today.

The groundwater contamination in the area, dubbed the "Capital City Plume," was discovered in 1991, but the disposal of the contaminated water likely took place from at least the 1940s to 1970s. Previous investigations were unable to identify the source of the contamination.

The current study, conducted by the USGS' Alabama and South Carolina Water Science Centers, in cooperation with Region 4 of the U.S. Environmental Protection Agency, collected information from 2008 to 2010 to investigate the potential source area of contaminants detected in groundwater; the pathway of the groundwater contamination; and the timeframe of when the contaminants might have been released.

Scientists collected pore water from Cypress Creek using passive-diffusion bag samplers; tissue samples from trees growing in areas in downtown Montgomery characterized by groundwater contamination and from trees growing along the Alabama River and Cypress Creek; and groundwater samples.

Analysis of the samples taken, combined with maps of historical land use since 1842, indicate that the perchloroethylene (PCE) and trichloroethylene (TCE)-contaminated shallow aquifer beneath the Capital City Plume site most likely resulted from past use and disposal of wastewater that contained chlorinated solvents into the sewer and stormwater systems by commercial printing industries that had occupied multiple locations in downtown Montgomery.

Results from the study also show that a source of PCE and TCE still exists in the ground near an original release area, providing a continual source of PCE and TCE to the shallow and intermediate parts of the shallow aquifer beneath the city.

The complete study is available online.

Southeastern Drought Worsens - USGS to Assess Impacts in Georgia, Florida and Alabama

OC_Web@usgs.gov (Office of Communications and Publishing) — Mon, 18 Jul 2011 14:06:47 EDT

ATLANTA, Ga. – Streamflow and groundwater conditions in southwestern Georgia and adjacent parts of Florida and Alabama continued to worsen during July. Waterways in many of the regions rivers are setting new record lows with gauges on the Flint, Suwannee, Ochlocknee, Alapaha, and Apalachicola rivers recording the lowest water levels in their history due to lower than normal rainfall. Groundwater levels were below normal and set new records in much of the southern Georgia, with some wells going dry.

To determine the impact of the drought on water resources and ecology of southwestern Georgia and adjacent parts of Florida and Alabama, almost two dozen researchers from three U.S. Geological Survey water science centers in Alabama, Florida and Georgia will conduct field studies in the Apalachicola-Chattahoochee-Flint and Aucilla-Suwannee-Ochlockonee river basins over the next 10 days.

"This is the first effort of its kind ever completed during the peak of the summer irrigation season", said Brian McCallum, assistant director of the USGS Georgia Water Science Center. "This effort will help us see hydrologic and ecological conditions at their most stressed condition."

USGS field crews will visit more than 200 stream sites and 400 private and public supply wells to assess streamflow decline and drops in groundwater levels. Additionally, field crews will collect water-quality information that will help in the determination of the drought's impact on ecological conditions in the region. Later in the summer, they will visit the same stream sites to assess populations of fish and mussels affected by drought conditions. The work is being completed as part of the USGS WaterSmart initiative, a program to assess sustainability of water supplies in the ACF basin.

Residents interested in monitoring water levels across the state or across the country have several USGS tools available for keeping informed, WaterAlert, WaterWatch, and GroundWaterWatch.

The USGS WaterAlert service sends e-mail or text (SMS) messages when certain parameters, as measured by a USGS real-time data-collection station, exceed user-definable thresholds which may vary at each gauge. For example users can input their favorite water gage, and receive updates on water level, streamflow, water temperature or salinity.

The USGS WaterWatch and GroundWater Watch websites display maps, graphs and tables describing real-time, recent and past stream flow and groundwater conditions for the United States, with real-time data updated on an hourly basis.

"WaterWatch and GroundWaterWatch systems are great tools to compare streamflow and groundwater levels in terms of historical context", McCallum said. Used in conjunction with the WaterAlert notification system, these systems provide a comprehensive tool for keep track of the hydrologic conditions in Georgia.

The USGS is the nation's primary provider of flow and water level information for our nation's waterways. For more than 125 years, the USGS has monitored selected streams and rivers with about 7,700 streamgaging sites and 20,000 wells across the nation.

Landsat 5 Satellite Sees Mississippi River Floodwaters Lingering

OC_Web@usgs.gov (Office of Communications and Publishing) — Thu, 16 Jun 2011 12:20:00 EDT

IMAGE FEATURE

In this Landsat 5 satellite image captured June 11, flooding is still evident both east and west of the Mississippi River near Vicksburg, Mississippi. Standing water is most apparent, however, in the floodplain between the Yazoo and Mississippi Rivers north and northwest of Vicksburg.

According to the National Weather Service, the Mississippi River reached a historic crest (57.10 feet) at Vicksburg on May 19, 2011.

By early June, flooding had receded considerably around Vicksburg, but water remained high. On June 14, the Mississippi River measured 44.88 feet at Vicksburg. At that point, the river was in minor flood stage and its level was forecast to continue falling through June 19.

The Landsat series of satellites is used by emergency managers to acquire a range of imagery, from floods to fires. Landsat has recently provided both images of the flooding of the Mississippi River and the fires raging in Arizona.

Landsat is a joint effort of both USGS and NASA. USGS conducts Landsat operations and NASA develops and launches new satellites that meet USGS requirements. In addition to imagery of natural hazard events, Landsat provides valuable data for land use research and advances the Department of the Interior’s important role in land remote sensing under the President’s National Space Policy. Landsat images are unique in that they provide complete global coverage, they are available for free, and they span nearly 40 years of continuous earth observation. No other satellite imagery has that combination of attributes.

Webcam now Monitoring Tallapoosa River

OC_Web@usgs.gov (Office of Communications and Publishing) — Tue, 7 Jun 2011 10:00:00 EDT

MONTGOMERY, Ala. -- The Tallapoosa River has new eyes. A webcam recently installed at the site of the historic May 2003 flood near Wadley, Ala., by the U.S Geological Survey’s Alabama Water Science Center is capturing live streaming video, enabling scientists, emergency managers and the public to visually monitor the Tallapoosa River’s water levels in real time.

Installed as a pilot project, the webcam is the first of its kind in the state, monitoring water levels and augmenting the existing USGS system of 11 streamgaging sites in the Tallapoosa River Basin which measure water levels, streamflow and rainfall.

“The visual record of water levels from the webcam adds value and verifies the data that is collected at the Tallapoosa streamgaging stations,” said Athena Clark, director of the USGS Alabama Water Science Center.

Streamgages provide critical information within minutes to many users including the National Weather Service, which issues flood warnings. Routinely, the information is used for water supply and management, monitoring floods and droughts, bridge and road design, determination of flood risk, and for many recreational activities. The addition of the webcam to the streamgages already in place provides another tool to monitor the river.

“The webcam can also be used as a management tool by local emergency response officials as they make decisions regarding safety of bridge crossings and evaluate extent of flooding in adjacent areas,” said Clark.

The webcam’s location is particularly important due to the significant flooding that occurred in and around Wadley in May 2003.

“Residents in this area are very sensitive to the possibility of flooding because of the 2003 flood. While residents should always follow emergency evacuation orders, this webcam will allow citizens to make informed decisions during unusual weather events that may lead to severe floods,” said USGS hydrologist Rick Treece.

“Installation of future webcams in Alabama will depend upon funding and the useful application of the Tallapoosa River webcam during flooding events,” said Clark.

To see live views from the Tallapoosa Webcam, visit the Tallapoosa webcam website.

Real time stream flow data from the more than 180 gauges in Alabama is used for flood preparedness tools such as USGS WaterAlert and StreaMail. Any member of the public can access current high flow and flood conditions across the country by visiting the USGS WaterWatch website. In addition, by signing up for USGS WaterAlert, people can receive instant, customized updates via text message or email about local water conditions or whenever a critical threshold is reached. People can stay informed, and more importantly, stay safe with such accurate, up to date information.

The USGS is the nation’s primary provider of flow and water level information for our nation’s waterways. For more than 125 years, the USGS has monitored selected streams and rivers with about 7,700 streamgaging sites across the nation.