Collage: USGS scientists handle a Burmese python in the Everglades; USGS scientists pull in a net full of mostly Bighead Carp ; two USGS scientists display a bighead Carp in the bottom left hand corner.

Over the last several decades, non-native species have continued to invade sensitive ecosystems in the United States.  Two high-profile species, Asian carp in the Midwest and Burmese pythons in the Everglades, are the focus of much attention by decision makers, the public and the media. USGS scientists will discuss issues related to invasive species and explain innovative methods used to help detect and control these invaders.

Time: Wednesday, July 11, 2012 • 7-8pm
Speakers: Sharon Gross, Robert Reed and Cynthia Kolar
Location: 12201 Sunrise Valley Drive Reston, VA 20192
Phone:  703-648-4748
Please Note: This event takes place at a Federal Facility — Photo Id is Required

FREE and Open to the Public
Follow this event live on Twitter @USGSLive

This announcement and directions can be found online.

Requests for accommodations (i.e. sign language interpreting) require notice at least two weeks before the event. Please email jcorley@usgs.gov or call 703-648-7770.

The USGS public lectures are held monthly in Reston, Virginia. These evening events are free to the public and intended to familiarize a general audience with science issues that are meaningful to their daily lives. USGS speakers are selected for their ability and enthusiasm to share their expertise with an audience that may be unfamiliar with the topic; speakers are encouraged to thoroughly explain the subject matter and to define any words or terms that may be unfamiliar.

The USGS lecture series provides the public an opportunity to interact with USGS scientists and ask questions about recent developments in Natural Hazards; Water; Energy Minerals and Environmental Health; Climate and Land Use Change; Ecosystems; and Core Science Systems. Ultimately, the goal is to create a better understanding of the importance and value of USGS science in action.

Bighead carp are a large and troublesome invasive species from Asia found in the great rivers of the central United States.

Under Siege! America’s Most Unwanted Invasive Species

The United States is under an economic and ecological siege by alien invaders — America’s Most Unwanted. More than 6,500 of these harmful non-native species cause more than 100 billion dollars in damage each year to the U.S. economy as the country battles to control the economic, ecological, and health threats these invaders pose. Increased global travel and trade are providing more pathways for both intentional and unintentional introductions of invasive species.

Invasive species affect just about everyone in every State in the country, in urban centers and wilderness areas. And their costs are borne by all of us — farmers, ranchers, businesses, and local, State, Tribal, and Federal governments.

The Cost of Invasives

Costly effects of invasives include crop decimation (cactus and gypsy moths), clogging of water facilities (quagga and zebra mussels) and waterways (hydrilla, giant salvinia), wildlife and human disease transmission (West Nile virus, monkeypox, and diseases in some ships’ ballast water), threats to commercial, native, and farmed fisheries (Asian carp, snakehead fish, sea lamprey, Asian swamp eel, whirling disease, and viral hemorrhagic septicemia), increased fire vulnerability (cheatgrass, brome, and buffelgrass) and adverse effects for ranchers and farmers (leafy spurge and cheatgrass).

Researchers with the USGS Invasive Species Program work on every one of those species mentioned; in fact, our researchers work collaboratively on all significant groups of invasive organisms in terrestrial and aquatic ecosystems in all regions of the United States. Across the Nation, our invasive species experts partner with States, other Federal agencies, businesses, agriculture, and natural resource managers to help solve the problems posed by these invaders.

Key components of invasive species activities include prevention, monitoring and forecasting threats, and control and management of established invaders.

During Invasive Species Awareness Week, we will feature some of America’s Most Unwanted each day to highlight the impacts of invasive species to the nation’s Ecosystems and economy.

Part 2

Asian Carp

In areas where Asian carp are abundant, they have interfered with commercial and recreational fishing, caused reductions in zooplankton (animal plankton, an important food for many aquatic species), and harmed native fish communities. Bighead and silver carp have moved up the Illinois River and are now poised to enter the Great Lakes. Resource managers fear that Asian carp would have ecological impacts and negatively affect the $7 billion-a-year fishery in the Great Lakes. Early USGS research focused on understanding the distribution, abundance, and habitat use of these fish, along with collecting information on their biology and life history from around the globe. USGS researchers are currently examining aspects of risk to the Great Lakes from Asian carp in the Chicago Area Waterways System, as well as conducting studies to develop and test ways to reduce the abundance and distribution of Asian carp.

Bighead carp are a large and troublesome invasive species from Asia found in the great rivers of the central United States.

Q: What are Asian carp?

There are many carp native to Asia, but in North America, “Asian carp” usually refers to bighead, black, grass, and silver carp — all of which are nuisance species in inland waterways. The Asian carp that have garnered the most attention are bighead and silver carp (together, the bigheaded carp), large fish that filter plankton from the water column. Grass carp primarily feed on aquatic vegetation, and black carp feed almost exclusively on mussels, clams, and snails. Grass carp (often sterilized to prevent reproduction) are sometimes stocked to control nuisance aquatic vegetation in lakes and ponds but can be considered a nuisance when they enter waters they were not intended to colonize or when they become established. Bighead, black, and grass carp are still sometimes used in aquaculture in North America.

Q: Why were they brought here?

Bighead and silver carp were imported to the United States in the early 1970s as a method of biological control of nuisance algal blooms in wastewater treatment plants and aquaculture ponds as well as for human food.

Q. How big do they get and what do they eat?

Both bighead and silver carp become fairly large; records of both species approach 100 pounds, but silver carp over 20 pounds and bighead carp over 30 pounds are uncommon. The North American record for bighead carp is a 106-pound fish from Missouri. Both bighead and silver carp feed on plankton, algae, bacteria, and detritus (various small, organic debris) — items that form the base of aquatic food webs.

Silver carp are a large a troublesome invasive species from Asia found in the great rivers of the central United States. Silver carp have been observed to jump in response to rocks thrown in the water, passing trains, geese taking off from the water, or just when they unexpectedly find themselves in a tight place. However, a speeding boat seems to especially frighten them and often dozens of the fish will be airborne at once, sometimes reaching heights of ten feet in the air.

Q: Where are they in the United States?

Asian carp are found in the great rivers of the central United States, especially in the Missouri, Illinois, and Mississippi Rivers. Bighead and silver carp are not known to be established outside the greater Mississippi and Mobile River basins, though individuals have been captured in many locations. However, experts are quite concerned about the risk of invasion by this species to other waterways in the United States, including the Great Lakes.

Q: How abundant are Asian carp in U.S. waters?

An exponential increase in the population numbers of bighead and silver carp began in the mid-90s and continued through the mid-2000s in parts of the Mississippi and Illinois rivers. The Illinois Natural History Survey has estimated that a population of more than 4,000 silver carp (almost 10 tons) per mile  exists between two Illinois River dams that limit their movement. USGS scientists hope to use genetic methods to determine the number of spawning Asian carp in different river reaches that are not bounded by dams.

Q: Do Asian carp affect native species?

Many studies show that bighead and silver carp substantially change ecosystems where they have been introduced. Studies around the world, including a USGS study in the Missouri River, found that zooplankton populations are dramatically reduced when Asian carp are abundant.  In the presence of high densities of silver carp, large phytoplankton (plant plankton) species decline, but very small phytoplankton species, too small to be fed on by silver carp, usually become more abundant. The end result is water that appears very green but has little zooplankton. Native fish that eat zooplankton may be negatively affected by Asian carp if food resources are limited. Furthermore, since nearly all fish feed on zooplankton when they are very young, most species have the potential to be affected. There is also evidence of native planktivores being out-competed by Asian carp for food resources in the U.S. as well as around the world.

Q: I’ve seen video footage of Asian carp jumping out of the water. Do people get hurt?

Silver carp have been observed to leap into the air simultaneously as an apparent fright reaction to rocks thrown in the water, passing trains, geese taking off from the water, or when they unexpectedly find themselves in a tight place. Speeding boats seem to especially frighten them, and often dozens of the fish will be airborne at once, sometimes reaching heights of 10 feet off the water. When they collide with boaters or property, injury and damage can result.

Q: Is it possible to eradicate Asian carp once they are in an area?

Eradication of any established population of Asian carp would be extremely difficult and expensive, if possible at all. Effective management of established invasive species that cannot be eradicated usually employs integrated pest management. This approach involves integrating as many feasible methods of control available for a given species into one management and control plan, each focused at the appropriate life stage and each applied most appropriately in time and space to achieve the desired level of control while minimizing economic costs and environmental risk. Generally, possible control methods include the use of fish poisons, physical barriers, physical removal, habitat alteration, or biological controls such as the addition of predators, parasites, or pathogens. Much research to potentially control the distribution or population size of Asian carp is ongoing as part of the Asian Carp Control Strategy Framework.

Q: How might I accidentally spread Asian carp?

The capture and movement of wild-caught baitfish is of special concern for spreading Asian carp. Young Asian carp could easily be transferred, as baitfish, from one body of water to another. In particular, juvenile silver carp sometimes school with gizzard shad and are similar in size, shape, and color. If you catch your own bait, in addition to being familiar with the bait regulations of your State, it is safest to use the bait only where it was caught and not to transport it to new waters, especially above dams.

Bighead carp are a large and troublesome invasive species from Asia found in the great rivers of the central United States.

Q. Can I eat Asian carp?

Asian carp of all types have white, firm, mild flesh, which is excellent table fare, but all Asian carp also have intramuscular bones in the filets that many people find undesirable. Asian carp feed low on the food web, are fast growing, are low in fat in the filets, and are not usually bottom feeders — all properties of fish that are lower in contaminants. Like any fish taken from inland waters, however, be aware of restrictions on consuming fish from any particular water way. For instructions on how to deal with the bones in Asian carp filets, see Flying Fish, Great Dish.

Carpé Carp!

Developmental rate and behavior of early life stages of bighead carp and silver carp

Asian carp recipe

UMESC Asian Carp Page

This large Burmese python, weighing 162 pounds and more than 15 feet long at the time of its capture in 2009, was caught alive in the Everglades and was found to have eaten an American alligator that measured about 6 feet in length. University of Florida researchers in the photo: Michael Rochford is holding the python's head, and Alex Wolf and Therese Walters are holding the python's body.

Under Siege! America’s Most Unwanted Invasive Species

The United States is under an economic and ecological siege by alien invaders — America’s Most Unwanted. More than 6,500 of these harmful non-native species cause more than 100 billion dollars in damage each year to the U.S. economy as the country battles to control the economic, ecological, and health threats these invaders pose. Increased global travel and trade are providing more pathways for both intentional and unintentional introductions of invasive species.

Invasive species affect just about everyone in every State in the country, in urban centers and wilderness areas. And their costs are borne by all of us — farmers, ranchers, businesses, and local, State, Tribal, and Federal governments.

The Cost of Invasives

Costly effects of invasives include crop decimation (cactus and gypsy moths), clogging of water facilities (quagga and zebra mussels) and waterways (hydrilla, giant salvinia), wildlife and human disease transmission (West Nile virus, monkeypox, and diseases in some ships’ ballast water), threats to commercial, native, and farmed fisheries (Asian carp, snakehead fish, sea lamprey, Asian swamp eel, whirling disease, and viral hemorrhagic septicemia), increased fire vulnerability (cheatgrass, brome, and buffelgrass) and adverse effects for ranchers and farmers (leafy spurge and cheatgrass).

Researchers with the USGS Invasive Species Program work on every one of those species mentioned; in fact, our researchers work collaboratively on all significant groups of invasive organisms in terrestrial and aquatic ecosystems in all regions of the United States. Across the Nation, our invasive species experts partner with States, other Federal agencies, businesses, agriculture, and natural resource managers to help solve the problems posed by these invaders.

Key components of invasive species activities include prevention, monitoring and forecasting threats, and control and management of established invaders.

During Invasive Species Awareness Week, we will feature some of America’s Most Unwanted each day to highlight the impacts of invasive species to the nation’s Ecosystems and economy.

Burmese pythons are now found across more than a thousand square miles of southern Florida, including all of Everglades National Park and areas to the north such as Big Cypress National Preserve. This snake threatens both the native animals and ecosystems in South Florida because they eat a wide variety of prey (mammals, birds, and alligators), and pose a risk to the ecosystems and the animals that live in them, including many including threatened and endangered species. Scientists do not know exactly how many Burmese pythons are living in Everglades National Park, but they believe at least tens of thousands are there.

USGS Research on Burmese Pythons

Recent USGS research provides initial evidence that pythons may be able to survive in marine and estuarine environments such as bays, inlets and open seas. This study showed that in the lab, hatchling Burmese pythons were able to withstand exposure to saltwater long enough to indicate that the species could potentially expand its range through ocean and estuarine environments. These results raise concerns that the constrictor may invade nearby islands, such as the Florida Keys.

Other recent USGS and partner research has demonstrated that some mammal species have declined  in areas where Burmese pythons are established in Everglades National Park. For example 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, observations 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. These mammal species were common in the park before pythons attained high densities, but research shows that their numbers have dropped dramatically over the same time that the pythons were becoming more abundant.

Fishing guide Camp Walker, Catalyst Charters, of Islamorada, Fla., took this photo of a Burmese python swimming in Florida Bay from the end of Twisty Channel toward End Key on Nov. 16, 2011.

Ongoing research may provide new tools that could limit python population numbers and help prevent further spread. In the meantime, agencies such as the USGS, National Park Service, Florida Fish and Wildlife Conservation Commission, and others are actively testing and applying control and eradication techniques, including trap development, refinement of visual searching methods, and testing detector dogs for locating pythons.

Brown Treesnakes

The invasive brown treesnake on the Pacific island of Guam is the poster child of the ecological and economic havoc an invasive species can cause. There, since the snake first invaded the island sometime right after World War II, mass extinctions of most of the island’s native birds, mammals, and lizards have occurred, which, in turn, have caused cascading and irreversible ecosystem changes.

For example, the loss of these native vertebrates means they are not available to disperse the seeds that pollinate trees and flowers. Consequently, some of the island’s native trees have greatly declined in abundance and may disappear. Similarly, as fish-eating birds have been lost from Guam by being eaten by the snakes, the natural nitrogen transport from aquatic and marine systems to bird rookeries has been lost as well, adversely affecting the growth of nitrogen-dependent plants on the island.

The Role of an Invasive

“Many invasive species take over the role previously occupied by a native species,” said USGS invasive snake expert Gordon Rodda, a scientist with the USGS Fort Collins Science Center. “While the non-native species might displace that native species, it doesn’t necessarily disrupt ecosystem processes. But when the brown treesnake came to Guam, it occupied a new role as a novel, arboreal night-time predator on birds, lizards, and mammals, a role to which these animals were not adapted.”

The result, said Rodda, is that with the extinction of most of the island’s vertebrates, the original ecosystem is simply not recoverable. It’s a cautionary tale for Florida where Burmese python populations are exploding.

Since Guam is overrun with brown treesnakes — as many as 13,000 per square mile in some places — current efforts focus on preventing them from invading the U.S. mainland or other snake-free islands such as the Northern Mariana Islands, Micronesia, and the Hawaiian Islands. This is challenging because shipping and air traffic from Guam to these other islands is a daily affair and because these snakes are masters at hiding in confined places where they can live a long time without food or water.

Prevention in Paramount

“Prevention of spread is paramount,” said Rodda. “It is much cheaper than intervention once a snake population establishes. With prey species that are unused to being hunted by snakes, invading brown treesnakes can remain well-fed with little effort while they continue to multiply. So it is crucial to keep alien species from sensitive environments.”

Without rigorous prevention, said Rodda, it is extremely difficult to control, let alone remove, an introduced reptile species. In the case of the brown treesnake, prevention efforts include working to detect stowaway snakes before they leave the island, as well as extreme vigilance on islands where the snakes are most likely to invade.

A multi-agency Rapid Response Team led by the USGS assists in detecting and capturing brown treesnakes that are found as stowaways or on other Pacific islands after being accidentally transported from Guam. This response team uses USGS research to help them improve their chances of finding snakes, as well as predicting the movements of snakes that could have accidentally made it to another island.

“If the brown treesnake gets to any of these other snake-free islands, it will find a veritable banquet of prey animals — and the same thing could happen there as happened on Guam,” Rodda noted. “It’s essential to get ahead of the curve and implement prevention efforts at the get-go, before an alien species becomes a problem.”

Of Parasites and Brown Treesnakes

As a consequence of being introduced to Guam in the late 1940s, brown treesnakes have been purged of the parasites that typically infect them in their native range, and which likely help keep their population numbers at reasonable levels. This freedom from natural parasitic enemies may help explain at least some of the ecological success of brown treesnakes on Guam.

Researchers at the USGS Western Ecological Research Center along with collaborators in Papua New Guinea, are investigating ways to exploit the natural parasitic and disease enemies of the snake as possible additional management tools for controlling the population on Guam, if not eradicating them altogether. Although much work remains to be done before experimental studies can begin on biocontrol efficacy, the findings of the USGS researchers to date are encouraging, and more exploratory work is on the horizon.

Eradicating this snake on Guam would have tremendous ecosystem, human health, and economic benefits, and would reduce the risk of invasion for other islands and the U.S. mainland.

Stalking Snakes:

Days (and Nights) in the Life of a Brown Treesnake Rapid Responder (contains a cool find-the-snake page to demo how difficult it is to see them!)

The Brown Treesnake on Guam

Brown Treesnake FAQs

Snakes in the Wrong Places: Gordon Rodda’s Career in Invasive Species Research

USGS Scientist Paul Hsieh, 2011 Federal Employee of the Year

The USGS scientist Dr. Paul Hsieh was named Federal Employee of the Year, highlighting the value of our science to the Nation. Hsieh was recognized by the Partnership for Public Servicefor his timely scientific analysis that convinced Federal leaders responding to the 2010 Deepwater Horizon oil spill that the cap placed over the Macondo well was working, allowing for a safe shutdown.

DOI Assistant Secretary Anne Castle Christens the USGS R/V Kaho. The Kaho is one of two sister ships that will begin research work in the Great Lakes.

USGS scientists worked on several regional and national issues. We contributed to the Great Lakes Restoration Initiative, including new treatment tools to help control Asian carp, an invasive species, and launch of new research vessels being deployed to understand the deep-water ecosystems and fishes of Lake Erie and Lake Ontario. USGS water quality monitoring and analysis, and water availability monitoring is taking place in waterways across the Nation at seven pilot locations that are part of the Urban Waters Federal Partnership: the Anacostia, Patapsco, Harlem, Bronx, and Los Angeles watersheds; the South Platte River, and the Lake Pontchartrain area. In the Grand Canyon, USGS science on uranium resources, hydrology, and the past impacts of mining informed the decision to withdraw Federal lands around the Grand Canyon from new mining claims. USGS science also played a significant role in Department of the Interior Natural Resource Damage Assessmentsettlements including the Deepwater Horizon oil spill and the Tyrone Mine area in New Mexico.

Wind turbines at certain sites in North America each cause dozens of bat fatalities per year.

On the new energy frontier the USGS continues to lead the way in the Department of the Interior with the release of “Wind Energy in the United States and Materials Required for the Land Based Wind Turbine Industry from 2010 Through 2030.” The data suggest that, with the exception of rare earth elements, there should not be a shortage of the principal materials required for electricity generation from wind energy. In the area of wind and wildlife, our scientists are using near-infrared videography to monitor and research bat activity at wind turbines, as a side effect of the expansion of wind energy is increased bird and bat mortality at turbines. We also continue to focus on conventional sources of energy development, evidenced in our summary report of the science needs for conventional energy development for the Chukchi and Beaufort seas. In the area of unconventional gas, the USGS worked with the Department of Energy and provided information for their report on the needed reforms for unconventional gas production, and the USGS is working with the Environmental Protection Agency and DOE on a strategy to fill those research gaps.

A submarine berg emerges from the advancing terminus of Yahtse Glacier. Iceberg calving is a key process in the global sea level budget.

In the area of climate change, the USGS completed the establishment of the eight climate science centers across the country with universities and consortia in Alaska, Colorado, Massachusetts, Oregon, Hawaii, Oklahoma, North Carolina, and Arizona. We also completed a study measuring the amount of stored carbon in the ecosystems of the Great Plains. This study was the first regional report that applied a comprehensive methodology designed by the USGS in 2010.

Scientists hike up the Little Colorado River to assist in installing remote PIT tag readers to more efficiently keep track of native, endangered fish populations.

Water continues to be a contentious issue in various parts of the country. In 2011, the USGS launched a geographic focus study on the Colorado River basin, part of the WaterSMART availability and land use assessment, a three-year study that will provide an inventory of water supply and demand. The effort includes assessing water needed to support ecosystems and will report significant competition over water resources and the factors causing the competition. Water information can also be sent to your email inbox or your phone, thanks to WaterAlert. This tool allows users to be notified daily of water levels at any of our 7,600 real-time streamgages across the country. Addressing the Nation’s water resource challenges is a priority for the USGS, and in 2011 we formed an innovative partnership to do just that with the U.S. Army Corps of Engineers and the National Oceanic and Atmospheric Administration. This partnership will provide a one-stop portal to integrated water information for stakeholders with forecasts showing where water for drinking, industry, and ecosystems will be available.

Josh Latimore stands in front of Burney Falls. Latimore started at the USGS as a summer intern and now serves as a USGS hydrologic technician while pursuing his bachelor of science.

The USGS engaged in a wide array of youth activities nationwide in 2011. From the collaboration with GeoFORCE at the University of Texas-Austin, to the National Cooperative Geologic Mapping Program’s EDMAP training component, to the Rocky Mountain Science and Sustainability Summer Academy (RMSSN). GeoFORCE engages minority high school students in the earth sciences, the EDMAP encourages high school graduates of this program to continue to work with the USGS throughout their college careers, and RMSSN provides training in field observation, data entry, and scientific communication to diverse students.

This map shows the various reported levels of shaking around Oklahoma City after the November 5 M5.6 earthquake

The Great Central U.S. ShakeOut drill, held in April of 2011, is just one example of the USGS’s role in preparing for and responding to natural hazards. Another example is the National Earthquake Information Center’s provision of real-time data to on the magnitude and potential damage of the August earthquake in Virginia, and the November earthquake and aftershocks in Oklahoma. To better monitor aftershocks, mobile seismic monitors were deployed, bringing the total of earthquake sensors in the Advanced National Seismic System to over 2,200. Flooding was also a concern last year, with more than 30 states affected. To educate Congress about the 2011 floods, we conducted a congressional briefing titled “2011 — The Year of the Flood?” For more than 100 years the USGS has played a critical role in reducing flood losses by operating a nationwide streamgage network that monitors the water level and flow of the Nation’s rivers and streams. This information was critical to the Army Corps of Engineers’ decision to simultaneously open the Mississippi River floodgates for the first time.

The 2006 image (left) show the river in a more normal state, while the 2011 image (right) shows the massive flooding. The dark blue tones represent water or flooded areas, the light green is cleared fields, and light tones are clouds.

During the heavy flooding that occurred on the Mississippi River, Missouri River, and other major waterways, the USGS’s Landsat satellites produced images of the affected areas to provide an overview of the situation. Landsat has often helped provide a big-picture perspective on natural hazards both domestic and foreign and ranging from tornados to tsunamis to wildfires. Landsat is a joint effort of both USGS and NASA. 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 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. To date, over 6 million scenes have been downloaded; over 2.6 million were downloaded in 2011.

These highlights are but a few of the USGS’s significant accomplishments and activities in 2011. Keep up with what we do in 2012 by visiting www.usgs.gov and following us on Twitter @usgs or on Facebook.

Gagehouse at 06225500 Wind River near Crowheart WY right before it washed away.