13 Apr 2011

Fish farming investigated as use for dairy effluent

1:55 pm on 13 April 2011

A project is underway in the Bay of Plenty to test the feasibility of developing fish farming as a sideline on some dairy farms.

It's one of the bright ideas dreamed up by Bay of Plenty Regional Council staff that's attracted funding from the council's newly-established innovation fund.

The idea, from Operations Manager Bruce Crabbe, involves using dairy effluent ponds as the starting point for a food chain for raising fish, either for commercial production or to build up native fish stocks.

The effluent would be used to grow algal bloom as a food source for phytoplankton, which in turn becomes a food source for fish.

Mr Crabbe says the cleaned and nutrient-free water from the fish ponds could be released into drainage canals and waterways.

He thinks it could be an alternative use for low-lying, marginal farm land in areas such as the eastern Bay of Plenty.

Bruce Crabbe says the $7500 dollar grant he's received will be used for a feasibility study on the economics of the idea.

In another project, a regional council environmental scientist, Jonathan Freeman is investigating the use of dairy effluent to generate heat and provide fertiliser for alternative horticultural land uses on Rotorua dairy farms, such as growing cut flowers, to reduce high nitrate use.