Taking big snapper and big crayfish out of an area lets kina run rampant. Ever seen a kina barren?
Putting the big snapper and big crayfish back is one thing we can do to keep our shallow reefs healthy.
- Big snapper and big crayfish deal to kina, keeping their population in check. Smaller snapper and crays can't do that job.
- When these big predators are removed from an area, kina numbers explode.
- Kina eat kelp.
- Left unchecked, kina munch through kelp forests, sometimes as deep as 8 m, leaving bare rock - kina barrens
- Kelp forests are the nurseries of the sea. When they are gone vital habitat for food, for cover and breeding is lost.
In a habitat survey around Waewaetorea and Okahu Islands in the Bay of Islands, it was found 65% of the sheltered reefs were kina barrens
- Download "Flagging Kelp" an essay by marine scientist John Booth 1.27mb
- Download "Wrecked Reefs" an essay by marine scientist John Booth 3.96mb
- Download "Urchin Barren Study" a report by biologist Vince Kerr 2.57mb
- Download "Waewaetorea Habitat Report" a report by biologist Vince Kerr and marine scientist Roger Grace 3.13mb
"We had no reason to believe that Kina Barrens, widespread throughout Northern NZ were anything but a natural occurence. We now know they are an artifact of overfishing. Kina Barrens have all but disappeared at Goat Island and Tawharanui Marine Reserves... "
Dr Roger Grace - Marine Scientist