the Hauraki Gulf
While the Hauraki Gulf is beautiful from the surface, below the waterline the ecosystem is in crisis. Kelp is vital for ocean ecosystems to flourish, creating habitats for marine life and is hugely efficient at fixing carbon. However, many coastlines which were once home to vast forests of kelp, now lie bare, thriving reef ecosystems replaced by kina (sea urchin) barrens.
In the Hauraki Gulf, scientists say the loss of large snapper and crayfish through over-fishing means kina are now grazing down the kelp beds at an alarming pace, without their natural predators to keep them in check. Areas that were previously dense in kelp are now barren. However, kelp beds can be restored and the flourishing beds within the Goat Island marine reserve are a shining local example.
“In New Zealand, it’s estimated that up to half of the kelp forest on shallow reefs around Hauturu-o-Toi (Little Barrier Island) is now gone. Our research is examining the role of marine protection and restoration in allowing kelp forests to bloom, and their associated marine life to return and flourish”
DR NICK SHEARS
Live Ocean Foundation is supporting work by Dr Nick Shears from the University of Auckland to understand both the scale of the problem and what happens when the kina are removed from barrens. Does ‘resetting’ the system accelerate the restoration of kelp on a large scale?
These findings could be very significant for new areas of marine protection, where kina removal could significantly accelerate habitat restoration. The research project is also investigating how kelp forests contribute to coastal carbon cycles.
In the south, kelp forests face different challenges, they are being impacted by sedimentation and an ocean that is already warming. This project builds from research developing of climate change resilient cultivars of Giant Kelp (Macrocystis pyrifera) to use in restoration.
The project led by Mat Desmond is a collaboration between researchers at the University of Otago and hapū of Te Rūnanga o Ngāi Tahu. Ngāti Wheke is working with Live Ocean to rebuild the kelp forests of Whakaraupō, offering the greatest chance of surviving in a warming ocean.