Also introduced for zooplankton control. Present only in government facilities and in Lake Orakai for experimental purposes. Silver carp were introduced in 1970 to test whether they could control phytoplankton boom in eutrophic lakes of the North Island. Stocks have been built up by artificial spawning and fish released in Lake Orakai. Here they were capable of controlling the phytoplankton blooms following nutrient build ups caused by rapid mixing of lake waters by winds. Their presence improved the appearance of the lake most of the time, but did not improve conditions for trout appreciably. At present (1994) stocks exist in Lake Orakai, Lake Omapere and a pond in Auckland; the future of this introduced fish in New Zealand is uncertain (Ref. 6452). Localized, non breeding in North I. Range is expanding (Ref. 52336). Also Ref. 11115.
Ref:
McDowall, R.M., 1984
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