International Ocean Acidification Week 8-10 September

Department of Conservation —  04/09/2020

A new program will monitor ocean acidity within marine reserves to get a national picture on how New Zealand’s moana will be affected by climate change.

A diver in a kelp forest at Taputeranga Marine Reserve in Wellington.
📷: Vincent Zinten

8-10th September is International Ocean Acidification Week

Ocean acidification is usually associated with poor ocean health, but this Monday we take the opportunity to celebrate DOC’s contribution to a nation-wide monitoring program that will help us track and respond to ocean acidification. This program is linked to the Global and New Zealand Ocean Acidification Observing Networks (GOA-ON and NZOA-ON), which are international and national collaborative efforts to monitor and understand ocean acidification. 

So far, the ocean has been protecting us from the worst effects of climate change. It’s estimated that, globally, the oceans have absorbed about 90% of the heat and 30-40% of all the carbon dioxide added to our atmosphere through human activities. This incredible ability for the ocean to buffer carbon dioxide has protected us from the worst effects, but we are quickly running up a debt that will be paid for by our marine ecosystems in the coming decades – and for centuries to come.

Ocean acidification doesn’t just affect the pāua, kuku, and other shellfish that we rely on for kaimoana. Many Zooplankton and phytoplankton are also threatened by the increasing acidity. Their important role as oxygen producers and the primary food producers of the ocean means that their struggles will affect nearly every other living thing – the whales, the seabirds, the people.

The importance of monitoring

Since 1998, NIWA and the University of Otago have been measuring ocean acidity off the Otago coastline, and 10 additional coastal sites have been operational for the past five years. In a new partnership with the NZOA-ON, DOC is committed to start monthly monitoring of ocean acidity at 9 sites around the country.

Ocean acidification will impact many industries, such as mussel farming.
📷: DOC

Currently, most ocean acidification monitoring is done in partnership with regional councils, local community groups, and other scientific institutions. DOC’s additional monitoring of 9 marine reserves around the country will give us valuable data on how ocean acidification will affect specific locations, and the country as a whole.

Organisms which use calcium carbonate as a building block, such as pāua and sponges, will be heavily affected as the ocean’s acidity increases.
📷: DOC

Marine reserves are particularly important areas to monitor climate change effects in the ocean. While marine reserves can protect against human factors, such as fishing and anchor damage, they don’t protect from large global factors such as acidification and sea level rise.

Monitoring ocean acidity within marine reserves will help us provide a ‘baseline’ for acidification with as few human influences as possible. Comparing the differences between reserves around the country will help us to predict which coastal areas will be most affected by climate change. This should help coastal communities prepare for local changes and help DOC prioritise habitats and species which will need conservation effort.

A large sponge growing on coralline algae in the waters off Great Barrier Island. It is still unknown how many species will respond to decreasing pH.
📷: Kim Westerkov

This new monitoring program is part of an extensive new framework which is being rolled out in New Zealand’s marine reserves this summer. Keep an eye out for the launch of the Marine Monitoring and Reporting Framework which is a powerful new tool for protecting our native marine biodiversity.  You can find out more about the New Zealand Ocean Acidification Observing Network here.