Friday December 13, 2019
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Contamination Of Contaminating Groundwater In Assam Remains A Silent Issue

"Climatic changes, like erratic rainfall which results in sudden long, dry spells, leads to less runoff water seeping into the ground and rejuvenating the water table. This results in increase in concentration of minerals like fluoride, that is pumped up by borewells."

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"When dilution of aquifers is low (because of erratic rainfall), the concentration (of minerals like fluoride) goes up," he said. And although Assam gets a good amount of rainfall, "the water table has depleted in some places". Pixabay

It’s peak election season. But, even as political parties go all out to appease voters, the worsening quality of groundwater hardly finds any mention.

In northeast India, Assam is in the middle of a grave groundwater contamination crisis. According to government estimates, fluoride contamination affects 23 districts and arsenic contamination affects 24 districts (out of a total 33) in the state. Even as people grapple to survive this basic necessity of life – excess fluoride can lead to dental and skeletal fluorosis, and arsenic is known to cause cancer – experts warn of a worsening situation in the future.

Understanding the root of a crisis is essential to finding its pragmatic solution, and in this context, Dr Manish Kumar, faculty at Discipline of Earth Science in IIT Gandhinagar, compared the situation to a glass of water in which spoonfuls of sugar are added. Until the water is saturated, it will keep dissolving the sugar, and then, the granules would start settling without further dissolution.

Likewise, minerals containing fluoride and arsenic found naturally in rocks of underground aquifers will dissolve more and leach more fluoride and arsenic under unsaturated conditions. Aquifers essentially constitute rocks and water, surrounded by microbes and organic matter.

“Any kind of anthropogenic stress on aquifers, like pumping, irrigation and return flow, leads to change in the saturation condition of groundwater and thereby enhances the release of arsenic (and fluoride) into the water,” Dr Kumar told this correspondent. Through extensive research on spatial distribution of geogenic contaminants across the Brahmaputra river, Dr Kumar and his team found the co-existence of arsenic, fluoride and uranium at some places.

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Likewise, minerals containing fluoride and arsenic found naturally in rocks of underground aquifers will dissolve more and leach more fluoride and arsenic under unsaturated conditions. Aquifers essentially constitute rocks and water, surrounded by microbes and organic matter. Pixabay

“We also found several places in Assam where the water is not yet saturated with arsenic and fluoride bearing minerals and thus prone to higher arsenic and fluoride concentration in their aquifers,” he said. In Nagaon district, for example, about 60 per cent of the samples tested were found to have “unsaturated” water.

Climatic factors like erratic rainfall, recharge and runoff also play a role in governing the weathering of minerals – otherwise found naturally – in groundwater, Dr Kumar said. The draft report of the Assam State Action Plan on Climate Change (2015-2020) states that Assam has been facing “continued warming of atmosphere” and “erratic rainfall” as a result of which there have been erratic flood and drought conditions since 2003.

Dr Robin Kumar Dutta, professor in the Chemical Sciences department of the Tezpur University, concurred with the linkage between climatic change and groundwater contamination.

“When dilution of aquifers is low (because of erratic rainfall), the concentration (of minerals like fluoride) goes up,” he said. And although Assam gets a good amount of rainfall, “the water table has depleted in some places”.

The issue, Dr Dutta added, also needs to be examined through the lens of geomorphology. “Karbi Anglong and Hojai, for example, fall in the rain shadow area and are among the fluoride-affected places in Assam,” he said. Dr Dutta has designed a low-cost filter technology to remove fluoride and arsenic (and iron) from water, which he has patented.

Cancer
ven as people grapple to survive this basic necessity of life – excess fluoride can lead to dental and skeletal fluorosis, and arsenic is known to cause cancer – experts warn of a worsening situation in the future.
VOA

Geomorphology, added activist Dharani Saikia, is why, at times, adjoining villages can have completely different results when their water is tested for fluoride (or arsenic) contamination. Working on the issue of fluoride contamination for many years now, particularly in the Nagaon and Hojai districts – two of the worst-affected in Assam – he stated the example of the Tapatjuri village.

“Tapatjuri in the Hojai district is one of the worst affected by fluoride contamination of groundwater. Any child you see here has stained teeth – the sign of dental fluorosis – and some have bent legs (skeletal fluorosis). In contrast, its nearby villages have no problem of fluoride contamination,” he explained.

“Climatic changes, like erratic rainfall which results in sudden long, dry spells, leads to less runoff water seeping into the ground and rejuvenating the water table. This results in increase in concentration of minerals like fluoride, that is pumped up by borewells,” Saikia further said.

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It is, however, not a hopeless situation and the key lies in revisiting and fine-tuning traditional methods. For instance, in Tapatjuri, the Public Health and Education Department (PHED) has put red-crosses on hand-pumps, indicating contamination. The villagers are now dependent on the PHED water supply from nearby rivers. (IANS)

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Here’s how a Small Stretch of Ocean Boosted a Conservation Movement

Know how a small stretch of ocean stirred a conservation movement

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Purple vase sponges are shown in this underwater photograph taken while scuba diving at Gray's Reef ocean. VOA

From the surface, these 22 square miles of water are unexceptional.But dip beneath the surface — go down 60 or 70 feet — and you’ll find a spectacular seascape. Sponges, barnacles and tube worms cover rocky ledges on the ocean floor, forming a “live bottom.”

Gray’s Reef is little more than a drop in the ocean 19 miles off the Georgia coast, but don’t confuse size for significance. In one of his last official acts, President Jimmy Carter declared the reef a national marine sanctuary at the urging of conservationists who said its abundance of life was unique and worth saving for future generations.

For nearly 40 years, the U.S. government has protected the reef, home to more than 200 species of fish and an amazing array of nearly 1,000 different kinds of invertebrates. Recreational fishing and diving are allowed, but commercial fishing and other kinds of exploitation are not.

And Gray’s Reef has served as a global inspiration. Following the lead of the U.S., other nations have designated similar sanctuaries and protected areas, which now cover about 6% of the world’s oceans — a bonanza for researchers but, more importantly, an important tool for safeguarding the seas.

Doubts remain about how much of the ocean they can truly save. Last year was the hottest on record for the planet’s oceans, and protected areas can’t slow the biggest source of that warming — increasing greenhouse gases. The federal government says more than 90% of the warming that has occurred on the planet over the past half-century has taken place in the ocean.

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A black sea bass swims along the reef in Gray’s Reef ocean. VOA

That has had dramatic effects in the waters that cover 70% of Earth’s surface. Scientists have tied the warming to the rise of sea levels, the disappearance of fish stocks and the bleaching of corals. The ocean also has become more acidic as humans have released higher concentrations of carbon dioxide into the atmosphere, and that jeopardizes valuable shellfish and the plankton that form the base of the food chain.

The supporters for the protected areas range from sustenance fishermen on the tiniest islands of the Pacific to researchers at the most elite institutions of academia.

“We’re not protecting these areas just for ourselves,” Roldan Munoz, a research fishery biologist with the U.S.’s National Marine Fisheries Service, says during a research trip to the reef, “they’re for our nation.”

On a National Oceanic and Atmospheric Administration expedition to Gray’s Reef, the federal research vessel Nancy Foster is packed with scientists conducting research on subjects ranging from whether invasive lionfish are present to how changing ocean conditions are affecting coral species.

Sanctuary research coordinator Kimberly Roberson and other scientists prepare to dive to collect data about what fish can be found in the area, while Craig Aumack, an assistant professor of biology at Georgia Southern University, peers through a microscope at algae.

Aumack notes that more types of seaweed and tropical species of fish are appearing on the reef as waters warm, like the odd-looking and colorful clown wrasse, a fish native to the Caribbean Sea that was found off the coast of Georgia this summer, most likely pushed hundreds of miles to the north by changing ocean temperatures.

The sanctuary is named after Milton “Sam” Gray, a biologist who studied it in the 1960s and identified it as an ecosystem worth saving — a reef not far from the U.S. coast that teemed with life, especially an “abundance of diversity of invertebrates,” Roberson notes.

Without that designation, the habitat could have vanished due to high-impact industries such as bottom-trawl commercial fishing, which are now prohibited there.

“In some ways, it’s a test of what a marine protected area can do for surrounding areas,” says Clark Alexander, director and professor at the University of Georgia Skidaway Institute of Oceanography and a former member of the sanctuary’s advisory board. “It was sort of an ideal spot to preserve this kind of habitat and make it available for research and recreation.”

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Scad and red snapper swim past divers Alison Soss, Geospatial Analyst, and Kimberly Roberson, Research Coordinator for Gray’s Reef ocean. VOA

In the decades since Gray’s was established, large and more stringently protected zones have popped up all over the world.

Phoenix Island Protected Area, established in January 2008, covers more than 150,000 square miles off the tiny island republic of Kiribati and has been cited by scientists for bringing back species of fish in just over a decade. And an area nearly twice as large, the Rapa Nui Marine Protected Area, now surrounds Easter Island after its creation in 2018.

Former U.S. Presidents George W. Bush and Barack Obama greatly expanded the U.S.’s protected areas. Bush created the Papahanaumokuakea Marine National Monument off Hawaii and Obama extended it late in his presidency to a whopping 582,578 square miles.

Smaller protected areas, such as the 5,000-square-mile Northeast Canyons and Seamounts National Monument off New England, created by Obama in 2016, also have been established.

Nine years ago, the U.N. Convention on Biological Diversity agreed to the goal of protecting 10% of the world’s oceans by 2020. The UN said in 2017 that it was on its way to meeting that target and that protected areas “contribute substantial social, economic and environmental benefits to society” and “provide food security and livelihood security for some 300 million people.”

One commonly cited problem with the protected areas is the difficulty of enforcing rules that restrict commercial fishing and other intrusive industries from vast areas where few people ever venture, particularly in developing parts of the world where resources are limited.

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Cannonball jellyfish float in the water as scuba divers surface after diving at Gray’s Reef National Marine Sanctuary. VOA

Creating new protected areas without reducing fishing quotas won’t save species, says Daniel Pauly, a professor of fisheries at the University of British Columbia in Vancouver.

And that is not a small issue, as some estimates say the number of fish in the ocean was reduced by half from 1970 to 2015, with warming oceans expected to add to that loss.

“Rebuilding will require not just new protected areas, but it will require quotas reduced,” Pauly says.

Many scientists believe protecting broad swaths of the ocean simply might not be enough.

Last year, a group of researchers led by University of North Carolina marine ecologist John Bruno published a pessimistic study of the effects of climate change on the world’s marine protected areas. Their findings: those areas will warm by nearly 5 degrees Fahrenheit by 2100, destroying species and marine life despite the existence of protections.

Bruno’s study reflects the reality of coral bleaching in places such as the Great Barrier Reef off Australia, which is heavily protected but still vulnerable to the impacts of a warming world.

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It’s a lesson that illustrates the legacy of Gray’s Reef: Protected areas can save pieces of the ocean from extinction, but they can’t save it all.

“If it was up to me, we’d protect about 30% of the ocean,” Bruno says. “We’re just saying we’ve got to directly address climate change with emission reduction. There’s no way around it.” (VOA)