Acidification Moorings

Summary

The Acidification Moorings sub-facility is responsible for building an ocean carbon and acidification monitoring network for Australian waters. The acidification moorings provide measurements of CO2 and related parameters.

The acidification of the global ocean’s surface waters is driven by CO2 uptake form the atmosphere. This process poses one of the most significant threats to the health and sustainability of Australia’s marine ecosystems. Evidence is already emerging of declines in calcification for tropical and polar marine species, but a lack of data on the changes in carbonate chemistry is making any link to ocean acidification tenuous. A network of moorings, combined with some underway observations in the SOOP program, provide key observations to address this problem for Australian waters.

Acidification moorings have been co-located at three National Reference Stations; Yongala in Queensland, off Maria Island, Tasmania, and off the west coast of Kangaroo Island, South Australia to cover both tropical and southern temperate waters. The co-location at the National Reference Sites provides meteorological and additional data to understand the controls on CO2 variability and ocean acidification. For various reasons, a fourth site at Heron Island which pre-dated IMOS has subsequently been brought into the network and Yongala has been paused.

The Yongala/Heron Island mooring provide high frequency data on the Great Barrier Reef, a region predicted to be strongly impacted by ocean acidification and this is the only acidification mooring of its kind on the Great Barrier Reef. The Maria Island mooring is located at a time series site that has been occupied for over 60 years and samples the influence of the East Australian current on CO2 uptake and ocean acidification.  The Kangaroo Island mooring monitors waters upwelled on the South Australian shelf which could result in the exposure of ecosystems to acidification earlier than in other regions. Both Kangaroo Island and Maria Island monitor southern temperate waters, which are predicted to undergo some major shifts in water chemistry that could disrupt marine ecosystems and impact shellfish production and possibly other fisheries of the region.

These are the only IMOS high-frequency shelf moorings for the measurement of CO2 parameters. The sites contribute to national and international research priorities, delivering to international data bases and the international Global Ocean Acidification Observing Network. The combined moorings and SOOP vastly improve temporal and spatial coverage for Australian waters.

Instrumentation

Each of the three sites is equipped with surface CO2 systems using proven and robust technology. These sensors determine surface CO2, dissolved oxygen, temperature and salinity. The pH sensors on the moorings are being tested and not yet considered robust enough to deploy more widely without further development to avoid biofouling.

Useful links

The National Mooring Network Publication Report. If you have any questions regarding the data, or corrections, or would like to add a publication or presentation that uses IMOS data please contact the IMOS office via email: publication(at)emii.org.au.

Contact:

Dr Bronte Tilbrook

Partner:

CSIRO Oceans and Atmosphere

International programs:

Global Ocean Acidification Observing Network

Surface Ocean CO2 Atlas 

United Nations Framework Convention on Climate Change

Your access to IMOS Acidification Moorings data discovery and exploration is through the Australian Ocean Data Network (AODN) Portal.