Regional dynamics in the marine climate of the Great Barrier Reef (C3.1)

Task leader: Dr Janice Lough, Australian Institute of Marine Science.

Task associate: Dr Paul Marshall, Great Barrier Reef Marine Park Authority.

Much of the ecology of the Great Barrier Reef, and how we can access and use its resources, is strongly determined by the physical environment (oceanography, weather and climate). The physical environment is not static and there can be substantial year-to-year variations as well as longer-term changes. This project includes a range of research tasks aimed at defining and modelling the nature and variability of the physical environment of the Great Barrier Reef World Heritage Area (GBRWHA) and assessing the sensitivity of marine ecosystems of the GBRWHA to varying oceanographic and climatic conditions. This will provide insights into the vulnerability and resilience of the GBRWHA to natural environmental variability and presently occurring and projected environmental change due to the enhanced Greenhouse effect.

Fundamental to this task are high-quality measurements of various components of the physical environment which are also made readily accessible to clients. Specific examples are:

• The Local Area Coverage satellite sea surface temperatures. These data are collected on a daily basis from the NOAA satellite at AIMS (Figure 1) and are processed to sea surface temperature using in-house algorithms developed specifically for the GBR region. The project will produce a CD-ROM Weather Atlas of the GBR,

• GBRMPA/CRC Reef in situ sea water temperature monitoring program. This program aims to build a comprehensive picture of sea temperature variations at various locations on reefs throughout the GBR. A total of 95 data loggers have been deployed which record water temperature at 30-minute intervals. Data are down-loaded every 6-12 months and summaries made available through the GBRMPA website. The sea temperature monitoring program captured comprehensive data during the 1998 coral bleaching event which may enable early warning systems to be developed for any future bleaching events (Figure 2).

Figure 1: Coral bleaching plotted on a satellite derived SST map for the Great Barrier Reef, February, 1998. (J. Lough, AIMS)

Figure 2: Water temperature variations at Nelly Bay from late December 1997 until March 1998. (R. Berkelmans, GBRMPA)