70 years of helping people to care for our ocean

Long-term monitoring of local coral communities stimulates exciting new areas of research

The ORI Coral team recently returned from its annual long-term coral monitoring field trip to the Sodwana Bay section of iSimangaliso Wetland Park. Each year permanently marked transects are surveyed and the underwater temperature recorders replaced with new ones by a team of scientists. This routine has been followed since 1993 making the project one of the oldest and most consistent of such nature in the world. Over 236 000 hourly temperature records have been logged and more than 10 000 coral colonies measured spanning nearly three decades, providing an invaluable resource for monitoring the impacts of climate change and other local stressors on the coral reefs.

The majority of marine ecological work is focused on the spatial dynamics of marine ecosystems as these studies yield instant results, yet relatively few investigations focus on the temporal dynamics of these systems as meaningful results and trends often take considerable time to manifest. Unfortunately, because of this, long-term monitoring projects do not attract funding despite their critical importance. Consequently, the dynamics of space and time, which underpin the functioning of the universe, and thereby coral reefs, are often not incorporated into such studies and neglected.

The data emanating from this long-term coral monitoring project have most recently been used to undertake an IUCN Red List assessment on the extinction risk of different types of coral reef ecosystem in the western Indian Ocean. The data have also been incorporated into a global report on the Status of Coral Reefs of the World soon to be published by the Global Coral Reef Monitoring Network in the next few months. Furthermore, the results have indicated how soft coral cover at the monitoring site has been consistently declining for no apparent reason until recent investigation by the ORI Coral team discovered surprisingly high levels of a range of organochlorine pesticides, including DDT, in the tissues of the corals that may be the cause for the decline.

Consequently, this nearly three-decade old project has resulted in several new avenues of research that would not have materialised without the valuable timeseries that has been generated and the necessary context to underpin further investigations into the health and resilience of our coral reefs and precious natural heritage into the future.