settled the historical claims of Te Uri o Hau, a hapu of the northern Kaipara Harbour. As part of the settlement, access to and the rights of the hapu to gather oysters within the existing "Maori Oyster Areas" were recognised. In 2008, resource consent was given to Biomarine to establish New Zealand's largest oyster farm in the Kaipara. The farm is projected to produce about NZ$30 million in annual exports and 100 new jobs. In recent years, there has been a perception amongst locals that commercial fishers have damaged fisheries in the Kaipara. Locals have been frustrated in their attempts to gain government support. The veteran filmmaker Barry Barclay has examined this in his 2005 documentary, The Kaipara affair. Sand mining Currently (2007) about 219,000 cubic metres of sand is mined each year from the entrance and tidal deltas of the Kaipara. This sand contributes over half the sand requirements for Auckland. The sand is used in the production of concrete and asphalt, and also in drainage systems and beach nourishment. A suction pump is usually used to extract the sand from the seabed. It is pumped into a barge as a sand and water slurry. As the barge loads, shells and other objects are screened out and the sea water drained back to the sea. The availability of sea sand within the Auckland region means the road costs of transporting sand from further parts of the country are avoided. Concerns about possible negative consequences of this sand mining have also been raised. Tidal power In 2008, Crest Energy, a power company, received resource consent to install about 200 underwater tidal turbines in the Kaipara Harbour, which would use the substantial tidal flows moving in and out every day near the harbour mouth to produce electricity for approximately 250,000 homes. Crest plans to place the turbines at least 30 metres deep along a ten kilometre stretch of the main channel. Historical charts show this stretch of the channel has changed little over 150 years. The output of the turbines will cycle twice daily with the predictable rise and fall of the tide. Each turbine will have a maximum output of 1.2 MW, and is expected to generate 0.75 MW averaged over time. The peak level of generation for the combined turbines is about 200 MW. This exceeds the projected peak electricity needs of Northland. It would have environmental benefits in