Quantcast

Farmed Salmon Industry Causing Global Sea Lice Crisis

A tiny bug is behind a major problem in the global farmed salmon industry.

The sea louse, or salmon louse, is eating into farmed Atlantic salmon supplies in Scotland, Norway, Iceland and Canada, driving salmon prices higher and creating a "chemical arms race in the seas," the Guardian reports.

Salmon companies around the world are spending an estimated $1.25 billion a year combined to tackle such outbreaks, the publication notes.

Salmon lice attach themselves onto wild or farmed salmon, living off the host fish's blood and skin and leaving it vulnerable to infections. As EcoWatch explained previously, crowded conditions in pens used for raising salmon can provide an ideal breeding ground for sea lice. In farms in some parts of the world, a pesticide is used to combat sea lice that is toxic to marine life and banned by both the European Union and U.S. Food and Drug Administration.

"What we are seeing now is a chemical arms race in the seas, just like on the land farms, where the resistance of plants to chemicals is growing," Don Staniford, head of the Global Alliance Against Industrial Aquaculture, told the Guardian. "In fish farms, the parasites are increasing resistance to chemicals and antibiotics. There has been a 10-fold increase in the use of some chemicals in the past 18 months."

Chemicals used to control salmon lice rose 932 percent on Scottish farms in the last decade, even though farmed salmon production only increased by 35 percent. Norway has ramped up its usage of hydrogen peroxide baths surged as well.

But like superweeds, salmon lice are growing resistant to such chemicals and antibiotics, leading some salmon farms to resort to potentially risky methods to beat back the parasite.

Staniford also described how some farms are using mechanical ways to remove the lice.

"They are using hydro-dousers, like huge carwashes, and thermal lousing, which heats them up," he said.

In Scotland, fish farming giant Marine Harvest used such a warming device called a thermolicer to delouse its caged salmon, but ended up accidentally killing 95,000 fish.

In Canada—where an infestation last year led to the deaths of more than half a million salmon—scientists are experimenting with using Pacific perch to clean lice from infested fish.

Some farms in Norway have successfully used this delousing method, deploying millions of wrasse to keep their salmon stocks healthy.

However, even that technique has a catch—a new study found that this practice may be depleting wild wrasse populations.

Keep reading... Show less

Nation's First Lawsuit Filed Against EPA's Scott Pruitt

By Brett VandenHeuvel

Thursday, Columbia Riverkeeper filed the nation's first lawsuit against the U.S. Environmental Protection Agency's administrator Scott Pruitt, Columbia Riverkeeper et al. v. Pruitt.

Pruitt has deep ties to the fossil fuel industry. As Attorney General of Oklahoma, he repeatedly sued the EPA to weaken environmental protections. It seems appropriate, then, that the first lawsuit against Pruitt could compel him to addresses the real impacts of climate change today. That's why we are in court, asking a federal judge to compel Pruitt to protect salmon from hot water—before it's too late.

Salmon need water cooler than 68°F for long-term survival, but the Columbia and Snake Rivers routinely exceed 70°F in the summer. And the water temperature continues to rise as our climate heats up. Low snow pack and record heat are becoming the new normal. For the Pacific Northwest, salmon are the canary in the climate change coal mine.

The summer of 2015 was a heart-breaking reminder of this long-recognized problem. That summer, I watched thousands of sockeye salmon swimming around in circles, scarred with lesions, waiting to die because they could not continue upstream to cold-water streams to spawn. Roughly 250,000 adult sockeye perished in the lower Columbia and Snake Rivers. Pollution—here, heat pollution—turned back almost entire run of Snake River sockeye salmon.

Climate change is not a future threat or something happening far away. It is impacting our quality of life, economy and local environment right now. The Columbia is just one example, but an important one.

Fortunately, there are things we can do right now to lower the water temperature in the Columbia and Snake Rivers. Dams on the Columbia and Snake Rivers create large, stagnant pools that warm up the water, but changing the operation of those dams to simulate more natural flows could reduce river temperature. And removing the four lower Snake River dams—which biologists have been recommending since the Clinton administration—could dramatically decrease the temperature of the lower Snake.

This lawsuit, if won, would require Pruitt to make a plan to protect salmon from the twin causes of hot water in the Columbia and Snake Rivers: climate change and dams. Under the Clean Water Act, the EPA must protect salmon from pollution, including heat pollution. We're asking a judge to order Pruitt to do his job: Acknowledge the immediate threat of climate change and make a plan to protect salmon.

The plaintiffs are Columbia Riverkeeper, Snake River Waterkeeper, Idaho Rivers United, Pacific Coast Federation of Fishermen's Associations and the Institute for Fisheries Resources. Plaintiffs are represented by: Bryan Hurlbutt, an attorney at Advocates for the West, a public interest nonprofit environmental law firm based in Boise, Idaho; Richard Smith, an attorney at Smith and Lowney PLLC in Seattle; and Miles Johnson, an attorney at Columbia Riverkeeper in Hood River, Oregon.

Sponsored
GMO

Judge to FDA: Agency Must Pull Aside Curtain on GE Salmon

By Jessica A. Knoblauch

A U.S. District Court judge took the U.S. Food and Drug Administration (FDA) to task on Jan. 10 for withholding government documents related to the agency's approval of genetically engineered (GE) salmon. The judge's decision is a big win for public transparency, but it's also a small step toward finally doing a proper evaluation of the risks posed by GE animals—which could one day end up on our dinner plates.

In 2015, the FDA approved GE salmon made from the DNA of three different animals: Atlantic salmon, deep water ocean eelpout, and Pacific Chinook salmon. The GE version is intended to grow faster than conventional farmed salmon, reportedly getting to commercial size in half the time.

Even though this is the first time any government in the world has approved a GE animal for commercial sale and consumption, so far the FDA has taken a lackadaisical approach to evaluating the salmon's potential for harm to wild salmon and the environment. If the GE salmon were to escape, it could threaten wild salmon populations by outcompeting them for scarce resources and habitat, by mating with endangered salmon species, and by introducing new diseases.

The world's preeminent experts on GE fish and risk assessment, as well as biologists at U.S. wildlife agencies charged with protecting fish and wildlife, heavily criticized the FDA for failing to evaluate these impacts. But the FDA ignored their concerns, so in March 2016, Earthjustice filed a lawsuit against the agency.

As part of the lawsuit, the FDA is required to compile a record of documents that illuminate the path the agency followed to reach its decision to approve the GE salmon—much like a student is required to show their work for a math problem in middle school. A complete record is essential in all cases. But it is especially important here because the FDA has so far refused to release most of the documents related to its decision, despite repeated requests for that information from Earthjustice's diverse set of clients under the Freedom of Information Act.

The public has a right to know how the agency came to this seemingly ill-informed decision, especially because the FDA's approach will likely serve as a precedent for the assessment of future GE food animals. Withholding that information is illegal because government agencies like the FDA are funded by taxpayer dollars, which means that any records they create, with only limited exceptions, can and should be available to the public and to citizens seeking to hold the government accountable in court.

Last month, a U.S. District Court judge agreed, concluding that: "the government is wrong to assert that these types of materials … should be excluded" from the record. The FDA is now required to fully complete the record with all relevant documents no later than July 2017. In addition to working to ensure the timely completion of that process, we will thoroughly review the full basis for the agency's decisions.

"There's no way to know what exactly is in these documents until we see them," says Earthjustice attorney Brettny Hardy. "But they will undoubtedly provide a far more complete picture of how we got here, including information that raises legitimate questions about the agency's decision."

Jessica Knoblauch is a former award-winning journalist who now serves at the helm of Earthjustice's editorial team, which tells stories through the organization's blog, quarterly magazine and website.

20 Most Read Posts of the Year

From Noam Chomsky's epic post on his fears of the coming Trump Administration to Michael Moore's damnation of the Flint water crisis to Robert F. Kennedy, Jr.'s first-hand account of the Standing Rock Sioux Tribe's fight against the Dakota Access Pipeline, 2016 was jam-packed with news once again showing our continued disregard for the health of people and the planet.

Though there were many positive news stories last year of people, companies and governments making strides to adopt sustainable practice and transition to renewable energy sources, the world's top scientists still fear the worse as atmospheric CO2 concentrations are just above 400 parts per million, taking us closer to the "danger zone" of 2 degrees celsius increase in temperature relative to pre-industrial time.

Many people think we have already reached the tipping point, but I believe power of people can turn this around. So, here's to a 2017 where millions more people become engaged on the most important environmental issues impacting the future of our planet.

Please read and share our content to get more people involved. You can like us on Facebook, follow us on Twitter and sign up to receive our Most Read News of the Day.

Here are EcoWatch's 20 most read posts of 2016:

1. Noam Chomsky: 'The Republican Party Has Become the Most Dangerous Organization in World History'

2. World's Largest Solar Project Would Generate Electricity 24 Hours a Day, Power 1 Million U.S. Homes

3. Solar Impulse Pilot: 'I Flew Over Plastic Waste As Big As a Continent'

4. Lake Powell: Going, Going, Gone?

Keep reading... Show less
Sponsored
Health

11 Health Benefits of Eating Salmon

By Franziska Spritzler

Salmon is one of the most nutritious foods on the planet.

This popular fatty fish is loaded with nutrients and may reduce risk factors for several diseases. It's also tasty, versatile and widely available.

Here are 11 amazing health benefits of salmon.

1. Rich in Omega-3 Fatty Acids

Salmon is one of the best sources of the long-chain omega-3 fatty acids EPA and DHA.

A 3.5-ounce (100-gram) portion of farmed salmon has 2.3 grams of long-chain omega-3 fatty acids, while the same portion of wild salmon contains 2.6 grams (1, 2).

Unlike most other fats, omega-3 fats are considered "essential," meaning you must get them from your diet since your body can't create them.

Although there is no recommended daily intake (RDI) of omega-3 fatty acids, many health organizations recommend that healthy adults get a minimum of 250–500 mg of combined EPA and DHA per day (3).

EPA and DHA have been credited with several health benefits, such as decreasing inflammation, lowering blood pressure, reducing the risk of cancer and improving the function of the cells that line your arteries (4, 5, 6, 7, 8).

A 2012 analysis of 16 controlled studies found that taking 0.45–4.5 grams of omega-3 fatty acids per day led to significant improvements in arterial function (8).

What's more, studies have shown that getting these omega-3 fats from fish increases levels in your body just as effectively as supplementing with fish oil capsules (9, 10).

As for how much fish to eat, consuming at least two servings of salmon per week can help meet your omega-3 fatty acid needs.

Bottom Line: Salmon is rich in long-chain omega-3 fatty acids, which have been shown to reduce inflammation, lower blood pressure and decrease risk factors for disease.

2. Great Source of Protein

Salmon is rich in high-quality protein.

Like omega-3 fats, protein is an essential nutrient that must be consumed through your diet.

Protein plays a number of important roles in the body, including helping your body heal after injury, protecting bone health and maintaining muscle mass during weight loss and the aging process (11, 12, 13, 14, 15).

Recent research has found that for optimal health, each meal should provide at least 20–30 grams of high-quality protein (16).

A 3.5-ounce serving of salmon contains 22–25 grams of protein (1, 2).

Bottom Line: Your body requires protein to heal, protect bone health and prevent muscle loss, among other things. Salmon provides 22–25 grams of protein per 3.5-ounce serving.

3. High in B Vitamins

Salmon is an excellent source of B vitamins.

Below is the B vitamin content in 3.5 ounces (100 grams) of wild salmon (2):

  • Vitamin B1 (thiamin): 18 percent of the RDI
  • Vitamin B2 (riboflavin): 29 percent of the RDI
  • Vitamin B3 (niacin): 50 percent of the RDI
  • Vitamin B5 (pantothenic acid): 19 percent of the RDI
  • Vitamin B6: 47 percent of the RDI
  • Vitamin B9 (folic acid): 7 percent of the RDI
  • Vitamin B12: 51 percent of the RDI

These vitamins are involved in several important processes in your body, including turning the food you eat into energy, creating and repairing DNA and reducing the inflammation that can lead to heart disease (17).

Studies have shown that all of the B vitamins work together to maintain optimal functioning of your brain and nervous system. Unfortunately, even people in developed countries may become deficient in one or more of these vitamins (18).

Bottom Line: Salmon is an excellent source of several B vitamins, which are needed for energy production, controlling inflammation and protecting heart and brain health.

4. Good Source of Potassium

Salmon is quite high in potassium.

This is especially true of wild salmon, which provides 18 percent of the RDI per 3.5 ounces, versus 11 percent for farmed (1, 2).

In fact, salmon contains more potassium than an equivalent amount of banana, which provides 10 percent of the RDI (19).

Potassium helps control your blood pressure. It also reduces your risk of stroke (20, 21, 22).

A large analysis of 31 studies found that supplementing with potassium significantly reduced blood pressure, especially when added to a high-sodium diet (22).

One of the ways in which potassium lowers blood pressure is by preventing excess water retention.

One study found that restricting potassium led to an increase in water retention and blood pressure in healthy people with normal blood pressure (23).

Bottom Line: 100 grams of salmon provide 11–18 percent of the RDI of potassium, which helps control blood pressure and prevent excess fluid retention.

Farmed Salmon Delivers Half the Omega-3s of Five Years Ago

We now need to eat two portions of farmed salmon to equal the amount of omega-3 intake that we would have gotten just five years ago, says a study from Stirling University in Scotland. The change appears to be due to a reduction in the amount of ground-up anchovies added to their feed.

Farm-raised and wild caught salmon contain the same amount of cholesterol, but wild salmon have half the fat of farmed in a typical half-filet serving.

Salmon farming is only about four decades old, but it is the fastest-growing food production system in the world according to WWF. Globally, about 3.5 million tons are caught or raised each year, and salmon accounts for 17 percent of the global seafood trade. About 70 percent of the world's salmon production is farmed.

Salmon is among the most popular seafoods in the U.S., where we eat 2.3 pounds per person each year. We prize salmon for its omega-3 fatty acids. National Oceanic and Atmospheric Administration (NOAA) says that consumption of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are key omega-3s found in seafood, may help to prevent high blood pressure, heart disease, certain types of cancer, clinical depression, anxiety and macular degeneration. Of the salmon consumed in the U.S., half is farm-raised.

Wild catch vs. farm-raised seafoodMarine Harvest

NOAA also states that farmed seafood is safe and healthy to eat, but many have questions about the practice. Crowded conditions in the pens used for raising salmon provide an ideal breeding ground for sea lice, which are now invading wild Alaskan salmon populations. Sea lice can be lethal to juvenile pink and chum salmon. In farms in some parts of the world, a pesticide is used to combat sea lice that is toxic to marine life and banned by both the European Union and U.S. Food and Drug Administration.

The greatest concern, though, centers around interbreeding of farmed and wild salmon. In September, a study by Canada's Department of Fisheries and Oceans found that more than 750,000 salmon have escaped from fish farms in Newfoundland since aquaculture began, and that these fish are breeding with wild salmon and producing offspring. A separate study in Norway found that half the wild salmon tested had genetic material from farmed fish. It's unclear which traits might impose themselves on wild salmon, but farm-raised fish are bred to grow big and to grow fast.

Farm-raised and wild caught salmon contain the same amount of cholesterol, but wild salmon have half the fat of farmed in a typical half-filet serving. Farmed fish also deliver three times the saturated fat as wild. But to feed a growing global population and provide the omega-3s they need, wild fisheries may not be up to the job.

On the West Coast of North America, salmon are in trouble. The number of endangered or threatened salmon runs on the Columbia River system has jumped from four to 13. In British Columbia, the sockeye salmon run this year was the lowest ever seen. Alaska's pink salmon catch is the worst it has been in 40 years.

Farmed salmon can still be ecologically friendly. According to WWF, it takes 10 to 12 pounds of feed to produce one pound of beef, but less than two pounds to yield a pound of salmon. Recognizing the need for fish farming, WWF worked to create global standards for salmon aquaculture designed to address the worst impacts. The Aquaculture Stewardship Council (ASC) now manages the standards and provides a certification program that retailers and consumers can use to ensure they are buying responsibly-farmed salmon.

The standards require farms to minimize diseases and the occurrence of sea lice while limiting the use of medicines to a set of strict conditions. Farms are also required to monitor and control water quality and prevent fish escapes as much as possible. The ASC also limits use of wild fish as feed, which is now seen to be responsible for reducing omega-3 levels in farmed salmon.

"We, and many others, are working very hard at developing new sustainable alternatives to fish oil and fish meal as sources of these long-chain omega-3s," wrote Dr. Douglas Tocher, one of the authors of the study, in an email to EcoWatch. "These include microalgal sources and genetically-modified oilseed crops."

The U.S. imports 91 percent of the seafood it consumes. Currently, oysters, clams and mussels account for tho-thirds of farmed seafood produced in the U.S., but NOAA opened up the hurricane-prone Gulf of Mexico to fish farms in January. That's the first time federal waters have been available for fish farming. So far, no commercial proposals have been received.

The World Bank estimates that almost two-thirds of the fish we eat in 2030 will be farm-raised. "Aquaculture will be an essential part of the solution to global food security," said Jim Anderson, bank advisor on fisheries, aquaculture and oceans for the World Bank Group. "We expect the aquaculture industry to improve its practices in line with expectations from the market for sustainable and responsibly produced seafood."

Aquaculture may also be the only answer to overfishing of the seas. Almost one third of global fish stocks are overfished, according to the United Nations. WWF says that stocks of all current food species of fish could collapse by 2048. But we'll need to feed 9 billion people by then.

"The solutions are very much in the pipeline," wrote Dr. Tocher. "Farmed salmon still deliver more omega-3 than wild salmon. And there is also absolutely no harm In eating two portions of farmed salmon."

Sponsored

World's Biggest Sockeye Run Shut Down as Wild Pacific Salmon Fight for Survival

Salmon have been swimming in Pacific Northwest waters for at least 7 million years, as indicated by fossils of large saber-tooth salmon found in the area. During that time, they've been a key species in intricate, interconnected coastal ecosystems, bringing nitrogen and other nutrients from the ocean and up streams and rivers to spawning grounds, feeding whales, bears and eagles and fertilizing the magnificent coastal rainforests along the way.

Salmon have been swimming in Pacific Northwest waters for at least seven million years.iStock

For as long as people have lived in the area, salmon have been an important food source and have helped shape cultural identities. But something is happening to Pacific coast salmon.

This year, British Columbia's sockeye salmon run was the lowest in recorded history. Commercial and First Nations fisheries on the world's biggest sockeye run on British Columbia's longest river, the Fraser, closed. Fewer than 900,000 sockeye out of a projected 2.2 million returned to the Fraser to spawn. Areas once teeming with salmon are all but empty.

Salmon define West Coast communities, especially Indigenous ones. The West Coast is a Pacific salmon forest. Today, salmon provide food and contribute to sustainable economies built on fishing and ecotourism. West Coast children learn about the salmon life cycle early in their studies.

Salmon migrations, stretching up to 3,000 kilometers, are among the world's most awe-inspiring. After spending adult lives in the ocean, salmon make the arduous trip up rivers against the current, returning to spawn and die where they hatched. Only one out of every thousand salmon manages to survive and return to its freshwater birthplace.

So what's going wrong? Climate change is amplifying a long list of stressors salmon already face. Sockeye salmon are sensitive to temperature changes, so higher ocean and river temperatures can have serious impacts. Even small degrees of warming can kill them. Low river flows from unusually small snowpacks linked to climate change make a tough journey even harder.

Oceans absorb the brunt of our climate pollution—more than 90 percent of emissions-trapped heat since the 1970s. Most warming takes place near the surface, where salmon travel, with the upper 75 meters warming 0.11 C per decade between 1971 and 2010. Although ocean temperatures have always fluctuated, climate change is lengthening those fluctuations. A giant mass of warmer-than-average water in the Pacific, known as "the blob," made ocean conditions even warmer, with El Niño adding to increased temperatures. Salmon have less food and face new predators migrating north to beat the heat.

Beyond creating poor environmental conditions for salmon, climate change increases disease risks. Warm conditions have led to sea lice outbreaks in farmed and wild salmon, and a heart and muscle inflammatory disease has been found in at least one farm. Scientists researching salmon movement through areas with farms are finding wild fish, especially young ones, with elevated parasite levels. Diseases that cause even slight deficiencies in swimming speed or feeding ability could make these marathon swimmers easy prey.

Some question whether wild salmon will remain a West Coast food staple. For the first time, the Monterey Bay Aquarium's Seafood Watch program has advised consumers to avoid buying chinook and coho from four South Coast fisheries. Researchers also predict changing conditions will drive important food fish north by up to 18 kilometers a decade.

Disappearing salmon don't just affect humans but all coastal ecosystems and wildlife. Eighty-two endangered southern resident killer whales depend on chinook salmon to survive. As chinook stocks go down, the likelihood that these whales could become extinct goes up.

Although the federal government has committed to implement recommendations from Justice Bruce Cohen's inquiry into Fraser River sockeye and to follow the Wild Salmon Policy, reversing this dire situation will take widespread concerted and immediate action. A weak provincial climate plan that fails to meet emissions targets and acceptance of new ocean-based fish farm applications won't help wild salmon. We need to move fish farms out of the water and onto land.

Salmon are resilient and have survived ice ages and other challenges over millions of years. They've survived having their streams paved over. They've survived toxins dumped into their environments. The question is, can they—and the ecosystems that depend on them—survive climate change and fish farms and all the other stressors humans are putting on them?

Health

Alarming Levels of Mercury Contamination Found Across Western North America

An international team of scientists led by the U.S Geological Survey (USGS) released a comprehensive report last week showing widespread mercury contamination across western North America.

The report, based on decades of mercury data and research, found alarming levels of mercury and methylmercury in the forests, fishes, wildlife, plants and waterways of America's western landscapes. The USGS study provides the first integrated analysis of where mercury occurs in western North America, how it moves through the environment, and the processes that influence its movement and transfer to aquatic and ultimately, the human food chain.

Fish are indicators of methylmercury contamination because they are an important link in the food chain for both wildlife and humans.U.S. Forest Service

Among the many disturbing findings are shocking accumulations of mercury in densely forested areas such as those found along the Pacific mountain ranges of California and Oregon. The scientific team showed that these critical ecosystems collect dangerous mercury loads because they receive high amounts of precipitation. Rainfall washes mercury from the atmosphere onto wet forested regions where it binds to the vegetation and accumulates in the soils and surface waters. From these vectors it can bioaccumulate in fish, including salmon.

Vegetation patterns affect both soil moisture and the amount of sunlight that reaches the soil, two factors associated with mercury release from soils.U.S. Fish and Wildlife Service

The report confirms the findings of a January 2016 study that narrowly investigated mercury levels in rainfall. That study reported that the long-term trend of decreasing mercury levels in precipitation had leveled off and that some sites in the western U.S. were experiencing increases, which the investigators concluded were due to exploding mercury emissions from Asia.

An earlier study in 2002 reported that industrial emissions in Asia are a major source of mercury in rainwater falling along the California coast. The new USGS study describes the precise atmospheric transport mechanisms that carry massive mercury contamination from Asia and deposit the potent neurotoxin in the water, soils and biota across America's West Coast. According to the papers lead author, it is not just the mercury itself, but a cocktail of atmospheric pollutants that contribute to the deposition of mercury in rainfall. Elemental mercury behaves as a gas in the atmosphere and is not washed out in rain until it has been oxidized into a charged ionic form that can be captured by water droplets.

The USGS study sheds light on earlier research with frightening human health implications. A 2008 study reported children living in areas of high precipitation may be more likely to have autism. Those investigators looked at rainfall in California, Washington and Oregon. That team obtained autism prevalence rates for children born in those three states between 1987 and 1999 and calculated average annual precipitation by county from 1987 to 2001. The researchers also computed the autism rates in relation to the average annual precipitation in the counties when the children were younger than 3 years old.

Those scientists found that counties that received relatively large amounts of precipitation had a relatively high rate of autism. More specifically, counties in Oregon and Washington west of the Cascades receive four times as much precipitation as counties east of the Cascades, and had an autism rate that was twice as high. These are the same states that were identified in the USGS's comprehensive report demonstrating the relationship between mercury deposition and precipitation.

The team also looked at each county over time, taking into account the varying annual precipitation levels. The study authors performed this analysis to rule out the effect of other factors, such as differences in the quality of the health care systems from one county to another. The relationship between precipitation and autism held.

Several earlier studies have established a potential connection between mercury from industrial air pollution and autism. In 2006 researchers in Texas reported that on average, for each 1,000 pounds of environmentally released mercury, there was a 43 percent increase in the rate of special education services and a 61 percent increase in the rate of autism. An investigation in the state of California found an association between autism and metal concentrations (mercury, cadmium, nickel, trichloroethylene) and possibly solvents (vinyl chloride).

These studies, however, concentrated on a few individual states. The latest study included women across the whole country. According to the first national study to investigate the possible link, living in an area with high levels of air pollution and mercury increased a woman's chances of having a child with autism.

"Women who were exposed to the highest levels of diesel or mercury in the air were twice as likely to have a child with autism than women who lived in the cleanest parts of the sample," according to the study author Andrea Roberts, a research associate with the Harvard School of Public Health.

Some researchers who first reported the correlation between high precipitation and high rates of autism, hypothesized that the link might be the result of children spending more time indoors where they generated less vitamin D or had increased exposures to household toxins. These reports gave little consideration to increased mercury exposure as a potential causative factor.

Key findings from the report include:

  • Methylmercury contamination in fish and birds is common in many areas throughout the West, and climate and land cover are some important factors influencing mercury contamination and availability to animals.
  • Fish and birds in many areas were found to have mercury concentrations above levels that have been associated with toxic effects.
  • Patterns of methylmercury exposure in fish and wildlife across the West differed from patterns of inorganic mercury on the landscape.
  • Some ecosystems and species are more sensitive to mercury contamination, and local environmental conditions are important factors influencing the creation and transfer of methylmercury through the food web.
  • Forest soils typically contain more inorganic mercury than soils in semi-arid environments, yet the highest levels of methylmercury in fish and wildlife occurred in semi-arid areas.
  • Vegetation patterns strongly influence the amount of mercury emitted to the atmosphere from soils.
  • Forested areas retain mercury from the atmosphere, whereas less vegetated areas tend to release mercury to the atmosphere.
  • Land disturbances, such as urban development, agriculture, and wildfires, are important factors in releasing inorganic mercury from the landscape, potentially making it available for biological uptake
  • Land and water management activities can strongly influence how methylmercury is created and transferred to fish, wildlife, and humans.

mail-copy

Get EcoWatch in your inbox