Most New Zealand ports developed in a similar pattern.
Establishment and growth
Numerous small, scattered ports appeared, each serving the immediate needs of its own community. As some of these ports grew into larger centres, they increased their share of imports and transhipments, and they increasingly prospered as railway lines ran out from their wharves to the interior. By 1881, for example, Dunedin, Wellington, Auckland and Lyttelton were dealing with 80% of overseas trade. The number of ports peaked in the mid-1860s, but fell from 86 in 1867 to 64 in 1881, a third of the remaining ports being in the under-developed Northland–Auckland area.
Eventually, lateral connections were made between ports, as road and rail links moved out along the coast from the bigger ports to siphon trade from the remaining struggling minor ports. This happened first along the Canterbury and Otago coasts. All the minor ports trading along the 50 nautical miles between Dunedin and Ōamaru, for example Waikouaiti, Shag Point, Moeraki, Kakanui and Allday Bay, died soon after the two towns were connected by rail in 1878. Elsewhere, geographical isolation, rough terrain or low population densities delayed such connection until well into the 20th century. Coastal shipping survived the closure of minor ports, switching to bigger, more efficient steam ships, and benefiting from the growth of the coal trade.