Fish tank plant poses threat to power station

Press, 13 May 1981, Page 10

Fish tank plant poses threat to power station

A common aquarium plant has been found growing wild in a Waitaki stream, and it is worrying New Zealand Electricity Division. N.Z.E.D. officers said that the plant, a common-oxygen weed, could cause serious recreation and hydro-electric power generation problems in the Waitaki system if it took hold in the lakes.

They have asked shop owners in Dunedin to consider stopping sales of the plant — Lagarosiphon — because of the potential threat.. The plant is found in Lake Wanaka, but it is being erad-

icated there. It is not common in the South Island. Big masses. of the weed could break loose and become clogged in hydro station intake screens, said the N.Z.E.D.’s Dunedin District Manager (Mr D. G. Dell), J „ , ... Lakes Rotorua and Rotoiti had been hard--hit by the weed, which can form a thick mat on top of the water at lake margins. A North Island hydro station had to be shut down completely when weeds blocked its intake screens. When the weed was recently discovered in Doctor’s Creek, near Kurow, the N.Z.E.D. decided on a full eradication attempt. AU aquatic plants and willows, along with the weed,

were cleared from the infested stretch of stream i The weed had spread along several kilometres of the creek before it was discovered. It appeared someone had planted the weed in a duck pond formed by a small dam along the stream.

Mr Dell said that the vteed was widely used in home aquariums, but there were other oxygen weeds sold by pet and garden shops that were only a minor nuisance in the South Island.

There were also littleknown native species that would make beautiful aquarA ium plants.. Eradication of the 1 nuisance weed was never certain, since only two or three centimetres of the plant could start a 'pew colony.