caused degradation to the environment of the harbour, destruction of traditional fishing grounds at the Oruarangi Creek, strong odours and swarms of Chironomus zealandicus (New Zealand midge) in the surrounding areas. The following year, the Māngere Residents' Protest Committee was formed to seek improvements or compensation. The plant was upgraded in 1983, but odour and midge problems persisted in Māngere Bridge. In the early 2000s the oxidation ponds were decommissioned and the treatment plant upgraded to use ultraviolet lamps to disinfect the sewage. As a part of the pond closure process, work on the ecological restoration of the harbour and shoreline began, resulting in the construction of the Watercare Coastal Walkway and an increase in migratory wading birds returning to the harbour. In 1970, planning began for State Highway 20 (commonly known as the Southwestern Motorway), an additional motorway connecting the Auckland CBD to Auckland Airport through Mount Roskill and Onehunga. Planning for this highway included a new motorway bridge to be built alongside the existing Māngere Bridge, and for the far eastern section of the suburb to be bisected by the new motorway. Construction on the bridge began in the mid 1970s. However, by May 1978, the construction halted when workers organised a labour strike over insufficient redundancy payments. The partially constructed bridge was picketed for a period of two and a half years, becoming the longest continuous labour strike in the history of New Zealand. The bridge was opened in 1983, and by 1984 State Highway 20 had extended south to Coronation Road, and to Massey Road by 1997. In 2010, a parallel motorway bridge over the Māngere Inlet was constructed, doubling the number of lanes to eight. The entire Western Ring Route project, connecting the Northwestern Motorway to the Southern Motorway was completed in 2017. In November 2018, the old Māngere Bridge was closed due to safety issues. A new, curved, pedestrian and cycling bridge will open by late August 2022. The proposals for the City Centre-to-Māngere light rail project involve a stop at Māngere Bridge, which may also involve a new crossing of the Māngere Inlet, separate to the Māngere Bridge pedestrian bridge and motorway bridges. In 2019, the name of the suburb was officially gazetted as Māngere Bridge, adding a macron to the suburb's name. Demographics Māngere Bridge covers and had an estimated population of as of with a population density of people per km2.