Lake Wairewa (Lake Forsyth) is a large, shallow, coastal lake, situated on Banks Peninsula, covering 627 hectrares with a maximum depth of 4 m. The lake holds high cultural significance among local Maori and is regarded as Mahinga Kai resource. The lake is often to subject to toxic cyanobacteria blooms, supported by high rates of phytoplankton growth (source lawa.co.nz)