The settlers killed many seals and chopped down trees with no thoughts for sustainability. This ruined the resource for the Maori. Some settlers got drunk and shot Maoris.
Wakefield New Zealand company brought out from England Thousands of settlers who needed land and houses and used lots of resources and crowded out the Maori.Most of the land was bought at an unfair cheap price.
Some time the settlers would say they have bought the land but the hadn't. Some times the settlers bought land from a Maori but not the Maori community.