No Surprise Here

Bay Journal, Mercury widespread in Chesapeake Bay headwaters fish. But we knew this already.

Nearly half of all gamefish in freshwater lakes, streams and rivers in the Chesapeake Bay watershed may be unsafe to eat because of high levels of mercury, a new study suggests.

In the first study to examine mercury across a spectrum of fish in the six-state region, scientists found that the pollutant remains prevalent in the environment in its most toxic form despite years of declining mercury emissions.

The totals vary widely by location, a possible indication that local conditions are raising or lowering the risk of contamination, according to the research conducted by three U.S. Geological Survey scientists.

“Our goal here was to really do a first cut of what we saw across the landscape,” said Collin Eagles-Smith, a USGS research ecologist. “Hopefully, that can be a springboard for future studies to get a better sense at why.”

The study centers on the type of mercury that is most toxic to humans: methylmercury. The neurotoxin is formed when inorganic mercury interacts with certain bacteria. It is particularly harmful to fetuses and children, potentially leading to intellectual deficits and problems with motor skills.

In the Chesapeake Bay watershed, mercury is the main trigger for fish-consumption advisories. Coal-fired power plants and trash incinerators are the largest sources of the pollutant in the region, scientists say. Once released into the air, mercury can travel great distances before getting deposited into waterways through rainfall or as a gas.

The Chesapeake watershed’s mercury levels — with 45% of all fish in the study exceeding the consumption standard — are similar to those found in many parts of the country, the authors say. The findings underscore the importance of checking for public health advisories before eating any wild-caught fish, said James Willacker, the study’s lead author.

Georgia used to work for the premier mercury biogeochemist from the Chesapeake Bay region, Dr. Cindy Gilmour, doing most of her mercury analysis in fish and a variety of other matrices. Mercury is, indeed, everywhere you look, if you have sensitive enough analytical techniques. And fish have so much it's not even particularly challenging.

In fact, many years ago, me and my fishing buddy Tom, who just happens to be Cindy's husband, helped catch a bunch of Striped Bass of varying sizes, from sub legal to 50 inches, and produced a data set that showed (not unexpectedly) that the concentrations of Hg were higher in larger fish, and that above about 30 inches, they usually had concentrations at which advisories would be recommended.

The techniques were well known, all that was necessary was for someone to go around and catch a few of each fish of edible size, from all the possible water ways, and analyze them. Oh, and somebody to pay for it. ICPMSs don't buy themselves.

The USGS researchers culled fish contamination records from two sources: a study conducted by the agency in the watershed from 2013–17 and state monitoring programs with reporting dating as far back as 1990.

Together, the collections contained measurements from nearly 8,000 fish caught in 600 locations.

The researchers found that the basin with the highest mercury concentrations was the Susquehanna. More than half of the basin’s freshwater areas ranked among the most toxic spots across the Chesapeake Bay watershed, which stretches from Virginia Beach, VA, to Cooperstown, NY.

Next was the Potomac, where 18% of waters landed in that tier. No water body outside of the Potomac and Susquehanna drainage areas fell into the most-polluted category. In contrast, at least half of the water bodies in the James, Rappahannock and York watersheds — all in Virginia — placed in the category with the lowest levels.

Eagles-Smith said it’s unclear why the watersheds in the northern end of the Chesapeake Bay basin have higher mercury levels in fish than those in the south. Regional air patterns would suggest the opposite — mercury tumbles from the atmosphere to the ground at higher rates in the South than in the North, according to the study.

Because methylmercury levels intensify with each step up food chain, the USGS scientists found the highest amounts in larger fish, including some of the region’s most prized sportfish.

 Ah, but where are the conditions better for the methylation of Hg, the step most necessary for its accumulation in fish?

Striped bass, a gamefish popular on restaurant menus, had the most mercury in its meat of the 32 fish tracked in the study, with a typical concentration of 0.31 parts per million. The U.S. Environmental Protection Agency has set a consumption limit for mercury of 0.3 parts per million.

“There are lots of people out there recreationally consuming that [fish],” said Betsy Nicholas, executive director of Waterkeepers Chesapeake. “These people don’t realize what they’re ingesting and how much of a detrimental impact that can have.”

Striped bass was followed, from more contaminated to less, by bowfin (0.2), walleye (0.19), largemouth bass (0.18) and flathead catfish (0.17), according to the report. The species with the least mercury included three types of trout and the creek chub.

“Trout are a great choice if you’re trying to avoid mercury exposure,” Eagles-Smith said.

Meh. If you're past reproductive age (or male) it takes a lot of Hg to be a real problem.



Wombat-socho has Rule 5 Sunday: Summer Musashi up and running as expected.

Uranus Stinks

Uranus

No Joke: Uranus Smells Terrible, Study Says

Uranus smells like rotten eggs, and that is not a joke. A new study finds that the seventh planet from the sun has an upper atmosphere flush with hydrogen sulfide.

Hydrogen sulfide is a gas best known for its repulsive smell; the gas emanates from sewers and volcanoes on Earth, explaining why some hot springs, which are fed by geothermally heated water, smell like breakfast gone bad. Astronomers have now discovered that the gas is common in the cloud tops of Uranus.

That hydrogen sulfide composition is different than what is found in the upper atmospheres of Uranus' fellow giant planets Jupiter and Saturn, where ammonia dominates, said Leigh Fletcher, a study co-author and senior research fellow in planetary science at the University of Leicester in England.
. . .
"If an unfortunate human were to ever descend through Uranus' clouds, they would be met with very unpleasant and odiferous conditions," study co-author Patrick Irwin, a professor of planetary physics at the University of Oxford, said in the statement. That is, they would if that person miraculously lived to take a whiff.

"Suffocation and exposure in the negative 200 degrees Celsius [minus 328 degrees Fahrenheit] atmosphere made of mostly hydrogen, helium and methane would take its toll long before the smell," Irwin added.

On the other hand, hydrogen sulfide is remarkably toxic, more toxic than hydrogen cyanide and for a similar reason, it binds cytochromes, and blocks cellular respiration. The only reason that isn't terribly well known is that the smell is so powerful and obnoxious it usually drives people away before they get a significant dose. However, the nose gets saturated by the odor, and that sometimes allows people to get poisoned.

Hydrogen sulfide is also the smell of "black mud", the result of the anaerobic decomposition of organic matter in the presence of sulfate, in a process called sulfate reduction, by sulfate reducing bacteria.

Georgia helped study the role sulfate reducing bacteria in the methylation of mercury. It turns out that many, but not all sulfate reducing bacteria can produce methyl mercury, the toxic form that accumulates in fish, and most of the methyl mercury in the environment is produced by them. Consequently, she and the lab she worked for, spent a lot of time visiting, sampling and measuring muddy environments with that nasty rotten egg odor. We jokingly called it the smell of money.

$50 M Settlement In Chesapeake Bay Area Mercury Spill

Actually, it wasn't so much a spill, as long term releases back before anyone understood the serious nature of the  problem: DuPont to pay $50M over mercury-contaminated Virginia rivers

Chemical giant DuPont will pay more than $50 million but admit no fault under a proposed environmental settlement after releasing toxic mercury for decades that made its way into Shenandoah Valley waterways, state and federal officials announced Thursday.

The deal would resolve alleged violations of civil environmental statutes, including the Clean Water Act, related to the pollution from a company factory in Waynesboro. It would amount to the largest environmental damage settlement in Virginia history and the eighth largest in the nation, officials said. The money would go to projects including wildlife habitat restoration, water quality enhancement and improvements to recreational areas.

"In bringing this settlement to a close, we are finally righting a wrong that has impacted the South River and the South Fork of the Shenandoah River for so many decades," Democratic Gov. Terry McAuliffe said at a news conference announcing the settlement.

Wilmington, Delaware-based Dupont Co. used mercury in its process of making synthetic fiber at the plant between 1929 and 1950, according to the state Department of Environmental Quality. Strict storage and disposal regulations weren't in place at the time, and some of the mercury seeped into the South River and flowed downstream to the South Fork of the Shenandoah River.

DuPont discovered the mercury — which accumulates in fish and is especially dangerous to pregnant or breastfeeding women and young children — in the facility's soil in 1976, officials say.

The pollution impacted over 100 miles of river and thousands of acres of floodplain and riparian habitat, affecting fish, mussels, migratory birds and amphibians, the Department of Justice said in a statement. The pollution also has limited some recreational fishing in Waynesboro, a city of about 20,000 in the Shenandoah Valley.

The terms of the settlement are outlined in a proposed consent decree that was filed in federal court in Harrisonburg on Thursday. It is subject to a 45-day public comment period and must be approved by the court.

When the City of Reading, PA lost 5 tons of mercury into the Schuylkill River over many years of using them as bearings in the trickling filters of their sewage treatment plants, the EPA made the city fund a study of the problem, and replace the mercury with another system.