He was furious that an independent commissioner had decided that the consent to mechanically remove the seedlings did not require public notification and that the consent had been granted.
Miss Skelton said mangroves were a protected native plant but they had been rapidly filling in open areas of the harbour.
"By removing seedlings before they get established we can prevent that spread into specific sites that have high recreational value."
But Mr Graham said mechanical removal had significant adverse effects to the environment.
"The vehicle will be going back and forth ... and will leave track which will be damaging to the environment. The removal of any mangroves is also significantly damaging and by doing this we are not planning for the future. We need the mangroves as the water levels in the harbour rise."