Everybody loves unagi, prepared on a grill and served with that delicious dark sauce, so may be a bit painful to read this: freshwater eel is one of the most destructive options at the sushi bar, and we need to cut way, way back.

It used to be these serpentine creatures were a complete unknown in the United States, their consumption restricted to small ethnic enclaves and unheard of within the general population. Things have changed. Unagi is now one of the five most popular choices in American sushi bars.

Wild populations of eels across the globe are in severe decline. These population crashes stem from habitat alteration, overexploitation, climate change, pollution, and disease. Even as stocks plummet, however, the demand for freshwater eel continues to grow. As wild stocks have diminished, aquaculture has taken over - about 90% of the eel consumed in the United States is produced in farms, mainly in China, Taiwan, Vietnam, and Japan. Unfortunately, eel aquaculture tends to be sloppy and has a number of serious problems.

Fish meal: Eels are carnivorous. When kept in captivity their keepers are forced to provide them with large amounts of protein. Regretably, local wild fish stocks are often targetted for this purpose. Researchers estimate that 2.5 metric tons of wild fish are needed to produce 1 metric ton of marketable eel.

Escapism and disease: Eels are adept at escaping from captivity. Most aquaculture systems that use modified wetlands and open systems see high levels of escapism. This leads to cross-breeding between wild and domesticated stock, possibly threatening future breeding patterns. Moreover, eels are susceptible to a large quantity of pathogens and may transfer diseases to wild populations upon escaping from aquaculture facilities.

Wetland destruction: Eel farms are often located in coastal wetlands, and most use open tank systems that flush farm waste into the surrounding areas, causing pollution and threatening local ecosystems.

The first step in tightening up this industry is to demand eel produced in farms with recirculating tank systems - a closed system that limits potential escapism and environmental damage. Until this occurs, we need to bring the demand for eel down to sustainable levels. Try to order unagi only on special occasions, maybe a few times a year, until the freshwater eel aquaculture industry cleans up its act. If you must have eel, consider ordering anago (conger eel.) Anago stocks aren't in great shape either, but every little bit helps.

Key Questions:

1) Is salt-water eel (Anago) available?

2) Is the unagi farmed or wild?

3) Does the farm use a recirculating tank system?*

*Chances are the chef won't know what you mean. But if we keep asking, they're bound to find out. We are the demand; make your voice heard.