Mangroves grow in the inter-tidal zone of tropical and sub-tropical regions. They are distinguished by their tolerance of salinity, and their adaptations for coping with a saline environment are of interest. They have many uses, both practical and indirect, for man, and evidence of the importance of their place in the food chain of marine life and as shore-line stabilisers is presented. New Zealand has one species of mangrove, and it is confined to sheltered waters of Northland and South Auckland. They have been exploited extensively by reclamation. Changes in reclamation policies arising from increased understanding of the role of mangroves are outlined, and administrative and legal problems arising from the intention to reserve mangroves are discussed.