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Entries in USGS (11)

Tuesday
Mar172015

Troublesome Invasive Plant Returns to Potomac River

Sassafras River Association volunteers collected these water chestnuts from creeks and streams on Maryland’s Eastern Shore

A troublesome old invasive has reared its head once again on the Potomac River. While sampling fish populations, biologists with Virginia Game and Inland Fisheries (VGIF) found a dense clump of water chestnuts, covering about ½ acre of water, near a boat rental dock in Pohick Bay Regional Park, 25 miles south of the nation’s capital.

Response was quick, as VGIF organized volunteers to hand pull the troublesome plant this past fall.

Water chestnut is probably a lot more troublesome and invasive potentially than snakeheads might be,” said biologist John Odenkirk.

“It was dense, but we got it. Hopefully, we nipped the potential for this plant to take over the bay and shut it down.”

Because it is an annual that sprouts from seeds, this fast-growing exotic is not susceptible to herbicides. It can be controlled only by pulling or mechanical harvest. The seeds have sharp needles that can attach to wildlife, clothing, and other items for transport to new areas, and they can remain viable in sediment for more than a decade. Just one acre of plants can yield enough seeds to cover 100 acres.

Native to both Asia and Europe, water chestnut was first confirmed on the Potomac in 1923, with a two-acre bed expanding to cover 41 miles of river, from Washington, D.C., to near Quantico, Va., in just two years. According to the U.S. Geological Survey (USGS), the dense, floating mats restricted navigation, harmed fisheries, and killed off submersed plants with their thick canopy.

The Army Corps of Engineers mechanically harvested the infestation and the plant was considered mostly eradicated from the Potomac by 1945. But limited hand harvesting continued into the 1960s.

USGS is studying this more recent invader to determine its species and lineage. Its spiny seed pods don’t resemble those of water chestnuts found in Maryland and other states. Additionally, VGIF and volunteer stewards will keep an eye out for future outbreaks. 

Tuesday
Nov252014

Water Conservation Improves as Use Declines

Water use across the country reached its lowest recorded level in nearly 45 years. According to a new USGS report, about 355 billion gallons of water per day (Bgal/d) were withdrawn for use in the entire United States during 2010, which represents a 13 percent reduction of water use from 2005 when about 410 Bgal/d were withdrawn and the lowest level since before 1970.

Reaching this 45-year low shows the positive trends in conservation that stem from improvements in water-use technologies and management. Even as the U.S. population continues to grow, people are learning to be more water conscious and do their part to help sustain the limited freshwater resources in the country.

Water withdrawn for thermoelectric power was the largest type of water use nationally, with the other leading uses being irrigation, public supply and self-supplied industrial water, respectively. Withdrawals declined in each of these categories. Collectively, all of these uses represented 94 percent of total withdrawals from 2005-2010.

Irrigation withdrawals in the United States continued to decline since 2005, and more croplands were reported as using higher-efficiency irrigation systems in 2010. Shifts toward more sprinkler and micro-irrigation systems nationally and declining withdrawals in the West have contributed to a drop in the national average application rate from 2.32 acre-feet per acre in 2005 to 2.07 acre-feet per acre in 2010.

For the first time, withdrawals for public water supply declined between 2005 and 2010, despite a 4 percent increase in the nation’s total population. The number of people served by public-supply systems continued to increase and the public-supply per capita use declined to 89 gallons per day in 2010 from 100 gallons per day in 2005.

Declines in industrial withdrawals can be attributed to factors such as greater efficiencies in industrial processes, more emphasis on water reuse and recycling, and the 2008 U.S. recession, resulting in lower industrial production in major water-using industries.

Read more here.

Wednesday
Mar122014

Asian Carp Eggs Found in Upper Mississippi River

 

Just when we think that we know what is going on with Asian carp . . . 

The U.S. Geological Survey (USGS) says that researchers found eggs, including late-stage embryos, in samples collected last summer from the Upper Mississippi River, as far north as Lynxville, Wisc. 

Here's more from the USGS:

"This discovery means that Asian carp spawned much farther north in the Mississippi than previously recorded," said Leon Carl, USGS Midwest Regional Director. "The presence of eggs in the samples indicates that spawning occurred, but we do not know if eggs hatched and survived or whether future spawning events would result in live fish."

The Asian carp eggs and late-stage embryos were discovered two weeks ago while processing samples that were collected in mid-May and mid-June, 2013. The samples were taken as part of a larger research project designed to identify Asian carp spawning habitats. The eggs and late-stage embryos were 250 river miles upstream of previously known reproductive populations in the river. Spawning would have occurred upstream from this site.

Once the scientists visually identified the eggs, they examined other samples taken from the Mississippi River and found Asian carp eggs at seven locations between Pool 19 near Keokuk, Iowa, and Pool 9 of the main channel of the Upper Mississippi River near Lynxville. Iowa, Missouri, Illinois, Minnesota and Wisconsin border the navigation pools where these samples were collected.

The eggs and late-stage embryos were identified as bigheaded carps — either bighead carp or silver carp — through visual analyses of specific features of the eggs and embryos. It is also possible that some eggs could be from grass carp, although no eggs were visually identified as such. The USGS attempted genetic analyses to definitively determine which species of Asian carp the eggs belong to, but the results were inconclusive. Additional steps are being completed to attempt genetic confirmation, and those results are expected in one to two weeks.

The research project that collected these eggs is being coordinated by the USGS in collaboration with Western Illinois University. Scientists plan to collect additional samples from the Mississippi River in 2014 as part of their on-going research project.

"Invasive Asian carp could pose substantial environmental risks and economic impacts to the Upper Mississippi River if they become established," Carl said. "Further research will help us to better understand their habitat requirements and inform integrated control efforts."  

Friday
Dec272013

Snakehead is Carrier of LMBV

Scientists have confirmed the presence of Largemouth Bass Virus (LMBV) in northern snakeheads taken from two Potomac River tributaries.

That might seem a positive development for those who view the exotic predator as a threat to bass and other native fish. After all, LMBV killed thousands of bass during the late 1990s and early 2000s; now maybe it will do the same to snakeheads.

But that’s not a foregone conclusion. The virus doesn’t always turn into a deadly disease. As a result, researchers caution that snakeheads simply could be carriers for spreading LMBV to bass throughout the Chesapeake Bay watershed, especially since the two share similar habitats.

“The virus has been found in bass, sunfish, and other fish species, but largemouth bass is the only species known to develop disease from it,” reported the U.S. Geological Survey (USGS).

USGS and Virginia Department of Game and Inland Fisheries made the discovery while studying snakeheads for possible pathogens. Until now, little has been known about what diseases this introduced predator might carry and/or be susceptible to.

In 2011, though, researchers found bass with LMBV in all 16 bodies of water tested in Virginia, except the tidal James River.

“The long-term and population-level effects of Largemouth Bass Virus on bass inhabiting these rivers are unknown,” added Luke Iwanowicz, a USGS research biologist.

Meanwhile, efforts to control the spread of snakeheads have been unsuccessful, the USGS pointed out, with scientists predicting they likely will expand their range.

Monday
Dec232013

Prescription Drugs Contaminating Lake Michigan

Prescription drugs and other chemicals are contaminating Lake Michigan as far as two miles from the Milwaukee sewage discharges, according to researchers. That’s an unpleasant surprise for those who had theorized that water was diluting the pollutants to non-threatening levels.

With 14 chemicals found at levels of “medium or high ecological risk,” scientists don’t know what effect they are having on fish and other aquatic life. But they are concerned.

“You’re not going to see fish die-offs but subtle changes in how the fish eat and socialize that can have a big impact down the road,” said Dana Kolpin, a research hydrologist for the U.S. Geological Survey. “With behavior changes and endocrine disruption, reproduction and survival problems may not rear their ugly head for generations.”

The chemicals’ ability to travel and remain at relatively high concentrations means that aquatic life is exposed, so there could be “some serious near-shore impacts,” added Rebecca Klaper, an associate professor at the University of Wisconsin-Milwaukee and senior author of the study published in the journal Chemosphere.

Of the 27 chemicals found, the most prevalent were caffeine, metformin (an antidiabetic drug), sulfamethoxazole (antibiotic), and triclosan, an antibacterial and antifungal compound found in soaps and other consumer products. The latter is known to be toxic to algae and can act as a hormone disruptor in fish.

The real problem, though, is the witch’s brew created by the contaminants blending together in the fishery. “It’s going to be hard to ease out which of these compounds may do harm,” Kolpin said.

Klaper added that the Milwaukee Metropolitan Sewerage District does a better job than other plants at removing many compounds. But its facilities are just not equipped to handle the volume.

“For example, we found quite a bit of caffeine in the lake, and they’re removing about 90 percent of the caffeine that comes in for treatment. They can’t remove everything.”

Capturing these pollutants is a challenge not just for Milwaukee’s treatment plants but for those across the country, according to Kevin Shafer, executive director of the Milwaukee Metropolitan Sewerage District.

“At the time wastewater treatment plants were developed, these compounds were just not an issue,” he said.

(This article appeared originally in B.A.S.S. Times.)