Historically, international shipping to and from New Zealand started out with the first explorer-traders, with New Zealand waters soon becoming a favourite goal for whalers as well as merchants trading with the Maori and beginning European colonies.
In the 19th century, one of the most important changes for New Zealand shipping – and for New Zealand itself – came with the introduction of refrigerated ships, which allowed New Zealand to export meat to overseas, primarily to the United Kingdom. This led to a booming agricultural industry which was suddenly offered a way to ship their goods to markets around the world.
Larger, deeper-draught ships from the middle of the 19th century made dredges a common sight in shipping channels around New Zealand, and tugboats were also often bought to assist them to the quays, where electric or hydraulic cranes were increasingly used for on- and off-loading. However, manpower was still needed in large amounts, and waterfronts were the hotbeds of the industrial actions of the early 20th century.[31]
In the 1970s, containerisation revolutionised shipping, eventually coming to New Zealand as well. The local harbour boards wrought massive changes on those ports selected (after much political wrangling) to handle the new giant vessels, such as Lyttelton and Auckland Port. Gantry cranes, straddle carriers and powerful tugboats were built or purchased, and shipping channels dredged deeper, while large areas of land were reclaimed to enable the new container terminals. The changes have been described as having been more radical than the changeover from sail to steam a century before.[32]
However, containerisation made many of the smaller ports suffer, this being only later recovered somewhat with newer, smaller multi-purpose ships that could travel to smaller ports, and the loosening of the trade links with the United Kingdom, which diversified the trade routes. The time for river ports had gone however, and most of them disappeared, facing particular pressure from the new rail ferries,[31][32] In the 1980s, deregulation also involved and heavily changed the port industry, with harbour boards abolished, and replaced by more commercially-focussed companies. Many port jobs were lost, though shipping costs fell