Rev. Samuel Marsden is believed to have been the first European to see the Manukau. Unlike the Rev. J. G. Butler who, after climbing Mount Wellington the day previous to Marsden's effort in 1820, described only the Maori settlements and plantations he had seen, Marsden specifically described the harbour itself. A few days later both missionaries crossed the harbour in a Maori canoe but could not navigate the entrance because of the heavy seas breaking on the bar.

The Manukau remained an important communications route throughout the early days of European settlement. During the Maori Wars local naval volunteers raided territories on the south side of the harbour from their base at Onehunga, established in 1847 as a defence outpost. Following the wars the harbour became important for its timber trade, kauri from Awhitu Peninsula and other timber from the Manukau lowlands to the south being rafted to the sawmills at Onehunga. Despite the treacherous nature of the entrance, the harbour was a regular call both for overseas ships and for coasters. Many ships have been lost here, the best known being HMS Orpheus, wrecked on 8 February 1863 with the loss of 189 lives. The early boom days of the harbour passed away with the construction of the railway south from the deeper and safer Waitemata Harbour. The first 10 miles were opened for traffic in 1873 and it is ironical that the puriri sleepers for it almost certainly came from the Manukau lowlands, across the harbour and through Onehunga. Growth of trade around the harbour has been slow and the urbanisation of the Tamaki Isthmus and the Manukau lowlands to the west of the harbour have been mainly related to the development of Waitemata Harbour. Most of the bush to the south has been cleared to make way for dairy and sheep farms, and the Waitakeres have been almost depleted of kauri. Today the harbour carries coastal shipping in slowly increasing tonnages to and from the industrial centre of Onehunga. An international airport, to be completed in 1965, is being built mainly on land reclaimed from the harbour near Mangere, where an extensive residential area is being planned. The Manukau waters still attract fishermen, and small but growing communities, such as Weymouth, which mainly depend on the recreational facilities of the harbour, have become established around the shores. Waiuku, on the south side of the harbour, is an important farming centre. Future development of the harbour will depend largely on the construction of a canal linking it with the Waitemata, where the tides are approximately two hours later. The canal would also shorten the sea route from the Waitemata to the west coast ports.

by Frederick Ernest Bowen, B.SC.(DURHAM), New Zealand Geological Survey, Otahuhu.

• Auckland – City of the Seas, Reed, A. W. (1955)
• South Auckland, Wily, H. E. R. L. (1939)
• New Zealand Geographer, Vol. 12 (1956), “Aspects of the Pleistocene and Recent History of the Auckland Isthmus”, Searle, E. J.