The Ministry of Agriculture and Forestry says a bacterial disease never seen before in New Zealand is leaving behind hundreds of deformed and dead kanakana or lamprey in Southland's Mataura river.
The jawless type of eel provides a valuable source of food for local Maori.
Last month, Hokonui Runanga chairman Rewi Alglem sent samples to MAF for testing, after finding kanakana with red- coloured fins and contusions on their bodies.
MAF's biosecurity response acting manager, Glen Neal, says tests have found the fish to be infected by the bacterium Aeromonas salmonicida.
He says the disease can affect salmon, trout, eel and whitebait species including kokopu.
Mr Neal says MAF is moving quickly to establish the potential impact of the disease, which hasn't been found before in New Zealand.
