Environmental implications of future offshore renewable energy development in Aotearoa New Zealand

Global climate mitigation efforts seeking to reduce greenhouse gas emissions require more renewable energy generation and utilisation. In Aotearoa New Zealand there are initiatives underway to develop offshore wind, or in the future, arrays of tidal turbines or wave energy converters, as a new energy resource. Here we synthesise available knowledge from international developments in offshore windfarm installations and discuss in a local Aotearoa New Zealand context. Aspects described include habitat modification, consequences of physical water column changes, and effects on benthic organisms, fish and fisheries, seabirds and marine mammals. Importantly, there is a need to adhere to Te Tiriti o Waitangi which defines Māori sovereign rights and expectations in terms of guardianship of resources (kaitiakitanga). Based on recent regulatory applications in marine spatial planning, where developments have been subject to the precautionary principle for environmental impacts, comprehensive environmental information will be critical for obtaining approval to proceed. The present synthesis identifies environmental pressure-points, footprints, and knowledge gaps, such as New Zealand-specific seabird and marine mammal behaviour and discusses potential opportunities to leverage the positive impacts of marine renewable energy developments.