date:Aug 09, 2012
lakes since they were introduced in the late 1960s from Malaysia. They are a natural aquatic weed controller and are unable to breed in the wild in New Zealand, unlike koi carp, which breed well and have become a pest species.
NIWA principal scientist aquatic plants, Dr John Clayton says as part of the study, the team built six large enclosures 2.5 metres deep and 6 metres wide, and placed them within hornwort beds in Lake Karapiro.
The cages contained different numbers of fish in order to es