Tag: china

Invasion of the apple snails

If you’ve seen these pink globular clusters near lakes and ponds, then it’s already too late – you’ve been invaded by apple snails from South America.

This notorious species was introduced to China in 1981 and has since spread throughout the warmer parts of the country.  It’s called 福壽螺 in Chinese, and is believed by many to be poisonous if eaten.  According to multiple sources on the internet, this appears to be untrue, although it is often a carrier of a frightening parasitic nematode.

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Dongjiang Expedition Part 4: The perils of small hydropower

Small hydropower, roughly defined as having 300 kilowatts to 30 megawatts of electricity generation capacity,  is often lauded as a low environmental impact solution for rural electrification.

In some cases, small hydropower may be useful and sustainable.  However, like large hydropower, its deployment must be planned carefully.  Small hydropower plants with reservoirs cause the same type of damage dealt by larger plants, including flooding of productive land, fragmentation of river ecosystems, and alteration of natural flows.

In-stream hydropower plants, which don’t require reservoirs, generate electricity by diverting water from the natural stream into sloped pipes that lead to turbines.  An important requirement for sustainable operation of in-stream hydropower plants is the maintenance of minimum ecological flow in the natural stream.

The over-deployment and poor planning of small hydropower has irreparably destroyed river ecosystems all over China, and Guangdong Province is no exception.

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Dongjiang Expedition Part 3: Mining – a devil’s bargain

Blocked mine shaft, labelled "Safe Production"

One of the most compelling books I’ve read in recent years is Collapse by Jared Diamond.  An important point he makes in the opening chapter is that there is often no way to operate a mine profitably provided that one accounts for all environmental externalities.  A simple example  is when an abandoned mine emits toxic run-off in perpetuity.  If mining companies had to bear the costs of treating this eternal source of pollution, there would be no price at which ore could be profitably sold because such costs would effectively be infinite.  Fortunately for mining companies, these externalities were largely ignored throughout human history and many have made huge profits at the expense of irreparably destroyed ecosystems.

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