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Raising Fish in Old Coal Mines: a Healthy Alternative?

US - In the Appalachian mountains of the United States, growing numbers of fish farmers are raising trout, catfish, and even salmon throughout the valleys of the state of West Virginia. What they'd rather not tell you, however, is that the source of their water is deserted coal mines.

Worry not, seafood lovers. According to independent experts from within West Virginia and outside the state, the farmers' claims of using 'clean, clear water' are true. The fish that are being raised in the mine waters are not only safe, but they may also be healthier than fish grown in conventional aquaculture operations, writes Ben Block for the Worldwatch Institute .

'The focus is less the mine water-we know it works, we know the fish are safe-and more of marketing,' said Ken Semmens, a West Virginia University aquaculture researcher who is promoting the mine-water operations.

Many abandoned coal mines in Appalachia are polluted with toxic metals. But some have been spared, and the water sources that accumulate are considered clean enough to raise fish. Pipes carry the water directly to the aquaculture operations without any treatment.

At the more polluted sites, coal companies are required to build treatment facilities that return the water to health. These purified water sources are abundant and growing in number [PDF] as the region's once-plentiful coal supplies are emptied.

By channeling water from the mines or adapting treatment facilities into farms, some dozen potential mine sites could supply water for large-scale fish farming-enough for about 45 tons (100,000 pounds) of fish per year, Semmens said. Hundreds of smaller streams are also being assessed to raise fish for recreational purposes.

'Buy Local' Applies to Fish, Too This creative use of mine water helps meet a growing global demand for fish. As marine fish stocks struggle due to overexploitation, the volume of farmed fish has doubled in the past decade. Aquaculture now supplies 42 percent of world seafood and could soon account for half of global production, according to a new report from the Worldwatch Institute, Farming Fish for the Future.

'As there is an increased concern for sustainable seafood production-[about] the carbon footprint of shipping fish halfway around the world-maybe fish grown locally will get a preferred place in the marketplace,' said Joe Hankins, director of the Freshwater Institute, the field office of the Virginia-based Conservation Fund. 'It may make the opportunity [of mine water-raised fish] more viable.'

But in West Virginia, fish farming is relatively new. The state's industry is ranked only 35th in value nationwide [PDF] and is geared mostly toward recreational fishers rather than the larger market of consumers along the East Coast.

Efforts to repurpose the abandoned coal mines began in 1994 when the state invested in a venture group called Minaqua (mining plus aquaculture) that it hoped would create 300 jobs from as many as 20 farms raising arctic char and rainbow trout. Those plans ended following a series of unfortunate incidents: a fish disease outbreak, a fire, and the death of the project's architect in a helicopter accident.

But the idea persisted, influenced by ideal aquaculture conditions. The water flows out of the coal mines at roughly 13 degrees Celsius (56 degrees Fahrenheit) year round, and unlike facilities that rely upon local streams, the water does not need to be pumped or diverted if it runs downhill naturally. Farms have been launched at four mine sites in the past eight years, and these are expanding.

'We plan to put a new farm online every year or two years. We see 10 years down the road between 1 and 2 million pounds of production. The water supply is that good in the state of West Virginia,' said Tom Ort, manager of Mountaineer Trout Farm in Princewick, near the state's southern border.

West Virginia University researchers are running demonstration farms as well, in the hopes of encouraging further investment. One farm captures water that flows from a treatment facility reservoir. A second has converted a former treatment plant into a fishing park. 'I started to think this is a wonderful resource we could have,' said Dan Miller, a research associate at WVU. 'Otherwise we would have to tear down the whole facility and blow up the concrete.'

The fish farms provide new opportunities for post-mining landscapes that are often of little use otherwise. But the operations can be applied only to deep mining locations, not to places damaged by surface mining activities such as mountaintop removal.

At Some Locations, Mine Water Is Safe

Aquaculture is not suited to all post-mining sites. Pyrite, a mineral better known as 'fool's gold,' is found throughout the coalfields of northern West Virginia. Pyrite contains high levels of sulfur and iron, which pollute the water that fills abandoned mines and raise its acidity beyond levels that many freshwater species tolerate.

At sites rich in pyrite, treatment facilities are required to balance the water's acidity. Even after treatment, minerals such as iron, aluminum, and magnesium remain at higher levels than are suggested for raising many fish species. But unlike mercury and many other toxins, these minerals do not accumulate in the fatty tissue of fish and endanger human health. 'The reality is it's really good,' Hankins said. 'And it's a resource that really should be looked at.'

The treatment reservoirs change temperature with the seasons, affecting fish growth during the colder months. As a result, most of West Virginia's mine-water farms are located farther south. Here, pyrite is not mixed in the coal, so treatment is unnecessary because the acidity and level of harmful metals are naturally within ranges suited for aquaculture, researchers said.

These fish farms also benefit from the fact that their water source is relatively isolated from exterior pollutants. Farmed fish often require antibiotics to ward off waterborne pathogens. Diseases are still a possibility in West Virginia, but the mine water is less likely to contain the dangerous pathogens. Also, water from within a coal mine is less likely to contain airborne mercury-a heavy metal that pollutes waterways after being released, ironically, from coal-fired power plants. Mercury is a neurotoxin that can accumulate in seafood.

One of the most serious environmental problems with aquaculture operations has been the run-off of fish waste into waterways, creating oxygen-free 'dead zones' where few species can survive. Blue Ridge Aquaculture owns a facility near Man, West Virginia, that plans to raise salmon in a closed system. The company says the operation will re-circulate the mine water and filter the waste, which could be sold as fertilizer.

State law, however, considers the aquaculture byproduct to be 'industrial' waste, so the fertilizer cannot be applied to agricultural farms and must instead be burned. 'West Virginia is behind in the legal structure,' WVU's Miller said. 'Farmers are screaming about the cost of nutrients going up. Here it is-we have fish poop.'

Supporters envision these farms providing income in a state where 16.9 percent of people live below the poverty line, the second highest poverty rate in the United States [PDF] But even the larger aquaculture operations do not create significant employment opportunities. Based on Miller's estimates, only six full-time jobs are created for every 450 tons (1 million pounds) of fish raised.

Still, with wild fish stocks plummeting and freshwater supplies dwindling worldwide, West Virginia's coal-mine fish farms could provide a much-needed resource. 'As long as rain falls on the state, the water will be there,' Hankins said. 'If we manage it properly, a lot of the former mined area...makes for a sustainable business opportunity.'