Disturbing new research shows great white sharks are now officially a 'threatened' species around New Zealand.
The New Zealand Threat Classification System report, released on Friday by the Department of Conservation (DoC), updated the conservation status of 113 species of sharks, rays and chimaeras found in New Zealand waters.
It found great white and basking shark numbers are worse than previously feared - downgrading their status from 'at risk' in 2005 - and the future of these species "is not positive".
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"New knowledge about great whites has confirmed an already suspected low adult population, which is either stable or in decline," says Conservation Minister Eugenie Sage.
"A recent population estimate puts the number of adult great white sharks in New Zealand at between 590 and 750 and the total population including juveniles at 5460 sharks.
"We know less about basking sharks but the lack of sightings of this large plankton-eater in former coastal hotspots such as Cook Strait, Kaikoura, around Banks Peninsula and off Otago is cause for concern."
DoC's marine technical advisor Clinton Duffy said research on shark numbers is worrying.
"We had assumed the population was low because of the slow breeding and growth rate of white sharks, but the numbers are a bit lower than we thought," he says.
"The main threats to white sharks in New Zealand waters are through accidental by-catch in fisheries, particularly for small juvenile sharks on long lines and adults in set nets."
Great white sharks are absolutely protected in New Zealand waters and if people accidentally catch one, they must release it immediately alive and unharmed, and are required to notify DoC.
But there was good news for some shark species. Four shark species improved their status to 'not threatened'.
"Just under half of New Zealand sharks, rays and chimaeras, 55 species, are categorised as 'not threatened', with large stable populations," Ms Sage says.
"But like much of the biodiversity in our vast marine area, our knowledge is patchy for this group; for over a third, 42 species, we don't know enough to assess their status."