Grass carp introduced into Maygrove Lake almost two years ago (HM July 13, 2015) have proved their worth, keeping weeds under control.
The water looks pristine at the northern end, where the fish are located. However, the southern end, that does not contain the fish, is markedly different – chocking up with a variety of weeds.
The lake was effectively dived into two parts with a net when the carp were introduced, in 2015, to prevent the fish entering the southern end where they could potentially be lost out to Orewa Estuary. Fish released in 2008 were washed over the weir and out to sea.
Until recently, a group of local residents maintained the lake, including wading in and removing large quantities of weed at least twice a year, but at the end of last year they told Auckland Council they would no longer continue to remove weed.
Maygrove Residents Association member Marie Walding says the group have only been doing edges and easy plant work because they wanted to prove the worth of the fish.
“In January we showed Council the effect that the fish have had in the northern end of the lake,” she says. “Council agreed that they need the fish in the southern end, and measured up for a screen to be built over the weir.”
Healthy Waters operations north team manger, Frank Tian, confirms that Council is considering removing the net from between the two parts of the pond to allow carp into the whole pond.
“Before this can be done, a grille will be designed and installed above the outlet weir to contain the fish,” he says.
Marie says that when the screen is put in place, the residents will gather for “a ceremonial pulling up of the net” from under the bridge.