November 13, 2007

Fish farms in US state of Idaho to face limit on phosphorus discharge

The US Environmental Protection Agency has now set a limit on the amount of phosphorus that can be discharged into the Snake River, which flows across southern Idaho.

Idaho is the nation's leading producer of commercial rainbow trout.

Phosphorus contained in fish feces is blamed for fueling algae blooms, diminishing water quality and reducing oxygen levels.

The permits, scheduled to take effect Dec. 1, require the industry to reduce by 40 percent the amount of phosphorus they discharge into the river.

The permits would cover aquaculture producers in the whole state but would centre around a 55-mile stretch of the Snake River that is the epicenter of the state's US$90 million a year aquaculture industry.