7 Mar 2024

Kina-nomics - The kina are taking over, what can we do?

From Voice of Tangaroa, 5:00 am on 7 March 2024
A man wearing a snorkel, mask and flippers dives down to a bare rock and uses an implement to scrape a kina sea urchin off the rock into a mesh bag, that is now full to the brim with kina. About four fish swim around the freediver, with more visible in the soft blue of the ocean in the backgorund.

Todd Herbert collects kina from a barren for Envirostrat, which is collaborating with Ngāti Porou Seafoods, international startup Urchinomics, and commercial fishers from Sea Urchin NZ. Photo: © Richard Robinson

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The kina are out of control. As many as 40 urchins crowd into a single square metre of rock, devoid of other life.

A kina barren is a symptom of an ecosystem out of balance. Could we eat our way to a solution?

Kina zombies

Kina numbers have exploded as we've eaten too many of their predators – like big snapper and crayfish – that usually keep them in check.

The urchins munch through kelp and seaweed, leaving bare rock and little else. The kina themselves end up suffering too – they persist in these zones as zombies, eating little and barely producing any roe.

Luckily, these barrens can be reversed and kelp forests restored when the kina are removed.

Putting kina on the table

Kina-nomics involves taking starving kina off reefs, fattening them up and selling them to an East Asian market.

But how can the kina be made more consistently tasty? And can economic and conservation goals really align? 

Listen to the episode to dive under the water with a kina harvester, taste some kina, and untangle whether a commercial harvest of these spiky taonga can really fix kina barrens.

A man wearing a hairnet, apron and thick gloves uses a device to pry open a sea urchin – one among a table full of hundreds of urchins. In the background another man in hairnet, apron and gloves sprays with a hose and two other men in similar attire work with urchins at another workbench.

At Peter Herbert’s kina factory on the Coromandel, Ashley Hine cracks kina open so his colleagues can scoop out the roe. Photo: © Richard Robinson

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Voice of Tangaroa is a joint production between RNZ’s Our Changing World and New Zealand Geographic.

Reporting for this series is Public Interest Journalism funded through NZ On Air. You can learn more and read the articles for free at www.nzgeo.com/seas