The major goal of coral records research in Australia is to produce continuous (annual or better resolution) records of climate and environmental conditions from at least 1700 AD to the present. Establishing the natural bounds of tropical climate via fossil corals should also be a high priority.

Intermediate goals include 

1. records for before and after European settlement in Australia, 

2. ENSO records for at least 100 years prior to enhanced greenhouse warming, 

3. high-resolution records for carefully chosen sub-periods (eg 30 year periods around major volcanic eruptions), 

4. making available data products on groups website.

The group identified the following clients for high-quality climatic and environmental records from massive corals: climatologists, environmental managers, water resource managers, civil engineers, primary industries (eg agriculture, mining), marine producers, town planners, scientific community, tourism industry, politicians, CRCs and ourselves.

The group agreed that the products we can develop could contribute to risk assessment, global change (climatic and environmental), assessing natural variability and identifying unnatural change, as well as education and expertise. Specific products include proxies for sea-surface temperature, rainfall, river flow, pollution, sedimentation rates, natural variability of reef ecosystems, and the health of reefs.

The group identified the following 12 areas for collaborative work under AUSCORE. The group welcomes others to participate in these activities and suggestions for additional collaborative projects.

1. Multi-proxy reproducibility of decadal-centennial scale SST variation on the GBR

2. Spatial variability and validation

3. Calcification mechanisms ? initial vs subsequent deposition

4. Trace elements in corals and seawater

5. In situ monitoring of corals and tissue thickness

6. Identification of environmental pollution

7. High-latitude corals

8. Genera other than Porites

9. Fossil corals

10. Oxygen isotopic composition of Indo-Australian seawater

11. Long-term monitoring of SST using the Sr/Ca thermometer in Porites corals from the northern GBR, western Pacific warm pool and central equatorial Pacific.

12. Calcification of soft corals

Objective: To reconstruct decadal-to-century SST on the GBR over the past 4 centuries and to assess the reliability of records obtained from different corals. It is hoped that the study will demonstrate that corals accurately record mean climate, by a number of means, throughout their entire life history.

Methods: A combined analysis will be undertaken of 4 of the longest coral cores from the central GBR; two inshore corals (Havannah, Pandora) and 2 outer shelf corals (Britomart, Lodestone). Density, extension, calcification, fluorescence, d18O, d13C, and Sr/Ca will be measured. Sr/Ca, d13C and d18O will be measured in skeletal samples with a resolution of 5 years. The purpose of the project is three-fold: 1) to compare the records obtained from different coral variables, 2) to compare the records obtained from different corals and 3) to produce a combined record of SST variation on the GBR that extends back over 400 years. The coarse resolution allows the analyses to be undertaken fairly rapidly to produce a long record. This record can then be used to focus in on particular time periods with higher temporal resolution.

Schedule: a) agree on 4 cores, b) undertake densitometry of 4 cores and fluorescence for 2 inshore cores (AIMS), c) Sr/Ca and d18O analyses of 5-year increments (ANU)

Importance: The project will a) demonstrate capability of group members to work together on a joint project, b) demonstrate the utility of comparing different coral records, c) validate common (climatic) signal in different corals, d) produce a climatologically relevant index of SST variations for Australia, e) extend beyond the ARTS ’ objective of climate in the 19th century, f) provide a basis for identifying unusual time periods to be studied in greater temporal detail.

Project coordinators: Erica Hendy, Mike Gagan, Malcolm McCulloch, Peter Isdale, Janice Lough.

Objective: To assess the reliability of different environmental recorders in coral skeletons, between colonies at the same site and across various environmental gradients of the GBR.

Methods: Joint analyses will be undertaken of a suite of coral colonies from inshore, midshelf and offshore reef locations in the northern, central and southern GBR. 3 corals will be analysed at each site, giving a total of 27 colonies. Density, extension, calcification, fluorescence, Sr:Ca and d18O. analyses will be undertaken at sub-annual resolution. Analyses will include inter-decadal time scale variability by including the wetter 1970s (vigorous monsoons) with the drier 1980s (less vigorous monsoons).

Schedule: a) identify coral colonies for analyses (AIMS), b) densitometry and fluorescence analyses of selected colonies (AIMS), c) Sr:Ca and d18O analyses (ANU), d) joint publication

Importance: There has been no comprehensive study of the degree of replication of records from corals (a fundamental principle of dendroclimatology). The project will provide a comprehensive data base for assessing a) the degree of replication between corals at the same site, b) the degree of replication between different locations on the GBR, both inshore to offshore and from north to south, c) how coral growth characteristics, which vary with reef location, may alter the recording of environmental information throughout the GBR.

Project coordinators: Janice Lough, Dave Barnes, Malcolm McCulloch, Mike Gagan

Objective: To test how thickening varies through the depth of the tissue layer at the outer surface of coral skeleton and beyond. eg is ratio of initial to subsequent thickening 60:40, 70:30 or what?

Methods: Two approaches will be used to assess this ratio: a) coral skeleton will be milled off and weighed (ANU), b) coral skeleton will be stained, a computer image taken, and milled off (AIMS)

Schedule: a) decide on coral material from colonies at AIMS, b) samples sent to ANU for analysis, c) analysis at AIMS (NB do we want to examine different parts of same colonies at ANU and AIMS?), d) joint publication

Importance: The ratio of initial to subsequent thickening is of prime importance to numerical models of coral growth and how materials are included in the skeleton during growth and thus, interpretation and resolution of inclusive records

Project coordinators: Dave Barnes, Ray Taylor and Malcolm McCulloch

Objective: To determine how trace element signatures in seawater are translated to a trace element signature in corals.

Methods: Water samples will be collected and analysed for trace elements and trace elements will be analysed in coral tissue and skeleton. Additional aquarium experiments may also be useful.

Schedule: To be decided

Importance: There is a need to understand how well or not trace element concentrations in seawater are recorded in coral skeletons.

Project coordinators: to be decided

Objective: To determine the range of natural variation in the thickness of the tissue layer in massive Porites, with a view to developing an "index of condition" representing the health and current performance of reef corals.

Methods: Permanent sites will be monitored along the length of the GBR. Colony tissue layer thickness will be measured at regular intervals to assess intra-annual variations. Will take advantage of opportunistic sampling and various in situ data loggers, eg GBRMPA and PAM fluorometer. Experimental manipulations of light and temperature will be used to evaluate forcing mechanisms of observed variations.

Schedule: Three years from 1997.

Importance: necessary to understand how good an indicator of "reef health" is the depth of the living tissue layer in massive species.

Project coordinator: James True, Dave Barnes

Objective: To determine how well massive coral species are recording environmental pollution and contaminants.

Methods: Worst case first, eg Misima Island (PNG), but also consider Jakarta and Townsville Harbours

Schedule: Misima Island corals already collected, density tracks done at AIMS, trace element analysis already proceeding at ANU

Importance: How are major environmental disturbances recorded in massive coral skeletons and what are the most reliable indicators?

Project coordinators: Stewart Fallon, Malcolm McCulloch and also link with Kathy Burns (AIMS).

Objective: To assess how coral growth characteristics, inclusive materials etc are recorded in corals growing near the limits of their range.

Methods: Questions to be addressed include: a) is there a winter stoppage of coral calcification and if so, where (geographically) is the switch-over between different modes of density band formation? b) development of numerical models for high-latitude corals will expand utility of models, c) nature of high density bands in tissue layer. Possible big corals in Moreton Bay.

Schedule: coral collected from Japan analysed for B, Mg, Sr, Ba and U at ANU and publication in progress

Importance: Most studies of records from massive corals have focussed on tropical sites. There is a clear need to assess the extent and reliability of records obtained from higher latitudes where corals are approaching the limits of their range (trees growing near the edge of their range are the most sensitive recorders of their environment, is this true for corals?).

Project coordinators: Vicki Harriott, Andy Steven, Lisa Roberts, Stewart Fallon, Dave Barnes, David Neil

Objective: Are other massive genera sensitive recorders of environmental conditions and changes in such conditions?

Methods: Identify existing material and collect additional material. Undertake isotopic, trace element and densitometric analyses.

Schedule: Opportunistic sampling of other massive species. X-radiographic, densitometric and isotopic and trace element analyses.

Importance: Australian work to date has focussed almost exclusively on Porites corals. Porites is a very robust species and is found in the entire range of coral reef environments ? from turbid inshore waters to pristine offshore reefs. There are other long-lived massive coral species whose utility as environmental recorders has not been explored. These species tend to have a more limited range and may be more sensitive than Porites to changes in their environment.

Project coordinators: Dave Barnes, Vicki Harriott, Stewart Fallon

Objective: Develop as complete a climatic picture as possible for windows of the more distant past; eg warmer and different rainfall patterns 6,000 years ago from central GBR

Methods: Identify existing material and collect additional material. Undertake isotopic, trace element and densitometric analyses. Possibility of fossil corals from higher latitudes, mid-Holocene ? tracking impact of humans through Moreton Bay and mid reef area 3-8,000 years ago Sr:Ca and d18O

Schedule: To be decided

Importance: Because of good preservation when dead, massive corals provide the capability (rare amongst sources of proxy climate records) to analyse well-dated windows of the distant past with a temporal resolution comparable to modern, living material.

Project coordinators: Mike Gagan, John Marshall, Scott Smithers

Objective: To develop baseline data of regional (and seasonal) oxygen isotopic composition of seawater in the GBR, Western Australia, and Indonesia/PNG, Japan/Taiwan.

Methods: Develop coordinated seawater, river flood plume, river, and rainfall sampling program involving AIMS (GBR and WA), project TROPICS (PNG), Indonesian Institute of Sciences, and the Geological Survey of Japan. Document regional and seasonal differences in seawater d18O, major river flood-plumes (Burdekin/Herbert, Sepik/Fly, etc), and perhaps rainfall during "cruises of opportunity".

Schedule: During AIMS cruises, project TROPICS, anyone - anywhere!

Importance: Very little is known about the oxygen isotopic composition of seawater in the northern Australia/Indonesia region, nor its relationship with salinity. This data set would be very valuable for chemical paleoceanographers, in general, and is important for "ground-truthing" the coral oxygen isotope data and reconstructing the P:E balance and paleomonsoons of the region.

Project coordinators: Mike Gagan, Miles Furnas/Alan Mitchell (AIMS), Gregg Brunskill (TROPICS), Wahyoe Hantoro (Indonesia), Atsushi Suzuki (Japan).

Objective: To produce multi-century records of SST variations in 3 key regions of the Pacific for monitoring past ENSO variability. Experience with Porites from the central GBR shows that ~75% of ENSO events can be traced using Sr/Ca. The project will complement other approaches (oxygen isotopes, trace elements) able to trace rainfall peaks related to ENSO (central Pacific) or anti-ENSO events (coastal GBR).

Methods: High-resolution sampling and variable resolution, high-precision analyses of Sr/Ca ratios by mass spectrometry linked with X-ray photographs and gamma densitometry.

Schedule: Coral cores (~ 300 years) have already been collected from Kavieng, PNG. Additional funds are necessary to drill corals near Lizard Island and Osprey Reef (GBR, permit granted from GBRMPA) and initiate a reconnaissance at Kiritimati (permit granted) and/or northern Solomon Islands.

Importance: The project will a) test the reproducibility of the Sr/Ca thermometer and validate the Sr/Ca derived temperature history of the Coral Sea-GBR, in particular the long-term temperature trends, b) document differences in skeletal growth processes in Porites from near-equatorial to tropical regions, c) identify the highest number of ENSO events as possible and use the major events as markers to improve the chronology of coral records near the equator where there is limited seasonal temperature variation, d) compare reconstructed SSTs from the western equatorial Pacific with similar records from corals in the eastern Pacific, allowing documentation of changes in the SST gradient between the 2 regions and thus ocean dynamics, e) produce a high-quality record of the frequency, intensity and decadal-century time-scale variability of past ENSO events and the intensity of trade winds. For selected time windows, high-frequency analysis should identify westerly wind bursts.

Project coordinators: Chantal Alibert, Janice Lough, Malcolm McCulloch

Objective: To measure calcification rates of soft corals

Methods: The deposition of calcium carbonate will be measured in vitro by 45 Ca kinetics in various genera of soft corals (Anthelia, Litophyton, Sarcophyton, Cladiella).

Schedule: The experimental work will be carried out at the European Oceanographic Centre, Monaco in the first 4 months of this project in late 1997. Completion of the analysis and preparation of a publication will be carried out at CQU in the last 2 months.

Importance: Most organisms within the class Anthozoa produce a calcareous skeleton. In general, soft corals (Alcyonaria) produce microscopic, non-fused, calcite sclerites. There is also evident of more complex calcification patterns in 2 genera of soft corals which, in addition, cement the bases of their colonies with a matrix of aragonite. Soft corals are an important component of coral reefs. On occasions they dominate the live cover of inshore reefs and they may be more tolerant to certain disturbances than hard corals. This study will provide the first measurements of calcification in this group of corals. The potential of soft coral skeletons for use as environmental recorders will also be assessed.

Project coordinator: Tina Tentori