November 2, 2007

US researchers taps 'sewer fish' for aquaculture
 

Aquaculture researchers in Kentucky State University have hit upon the perfect candidate for aquaculture, in an unlikely location - sewer waters - treated water that is.

The researchers have announced they have raised 40,000 paddlefish in decommissioned wastewater tanks at the Frankfort Sewer Department during summer.

The researchers used processed water, at a decommissioned water treatment plant for their aquaculture project.

According to researcher Dr Steven Mims, the water pass EPA standards and is near drinking-water quality.

Treatment facilities often develop problems with an overabundance of the zooplankton "daphnia." Too much of it can clog up the tanks and prevent solids from filtering out, affecting water quality.

Young paddlefish however, thrive on daphnia. In the business sense, it is free feed. At the same time, paddlefish help clean up the sewer plant, Dr Mims pointed out. The team was able to haul hundreds of pounds of daphnia from the plant initially.

However, the 'free lunch' was only able to last a month for the 40,000 fishes after which the team switched to pelleted feed for the next three months.

The paddlefish will be put into lakes to mature and be harvested for caviar and boneless meat.

As sturgeon caviar has become scarce, prices for paddlefish caviar have soared over the years, increasing the viability of the venture.