Earth and Environment

Our current projects

 

Our research area covers a large part of the Western Australian coast but also extends to the southwestern and southeastern Indian Ocean. 

  1. Hydrodynamics of the Western Australian coastal area and coral reefs
  2. Southern Indian Ocean climate change
  3. Ocean acidification

Hydrodynamics at of the Western Australian coastal area and coral reefs

  • Coastal and estuarine hydrodynamics
  • Numerical modelling of waves and coastal circulation
  • Carbonate chemistry at Ningaloo Reef
  • Sediment movement at Ningaloo

Southern Indian Ocean climate change

Southern Indian Ocean climate change 

Coral core study sites from the southwestern and southeastern Indian Ocean superimposed on the Indian Ocean Dipole spatial pattern for sea surface temperature (SST), and locations of other important SST dipoles.

Climate change of Australia’s NW marine environment: 200-300 year records from geochemical proxies in massive corals and its implications for Australian rainfall patterns

This study proposes to examine the spatial and temporal environmental and climatological changes affecting coral reef ecosystems across the northwestern shelf of Australia over the past 300 years. To meet this goal I will examine several biological (growth rate, density, calcification) and environmental parameters (luminescence, trace elements, stable isotopes) in massive coral skeletons of the species Porites sp. which continuously grow for up to 300 years. As an overarching objective, I aim to determine how basin-wide Indian Ocean (IO) climate phenomena affect Australian and circum IO climate, i.e. Indian Ocean Dipole Mode (IOD), Subtropical Dipole Mode (SDM), by combining my previous and ongoing research on corals from the western Indian Ocean with those newly obtained off Australia from the eastern Indian Ocean.

CLIMATCH - Climatic and anthropogenic change in seasonal river runoff and impacting cyclones resolved by novel spectral geochemistry of giant corals in Indian Ocean catchments (Dutch NWO-ALW project)

Changing river runoff into marine catchments is recorded by giant corals that incorporate soil-derived humic acids in their carbonate skeleton. We developed novel, rapid techniques of spectral geochemistry to fingerprint skeletal growth banding in cores taken from giant, centuries old Porites with unprecedented, weekly resolution. As a primary objective, CLIMATCH will determine the climatic baselevel changes in runoff due to multi-decadal climate variability and extreme erosion events along the path of cyclones over the past 350 years and for Holocene time slices. As a second objective, CLIMATCH will assess anthropogenic impacts on river runoff in Indian Ocean catchments as offsets from these climatic baselevels in hotspots of land degradation, i.e. Mauritius, iconic Madagascar and Mozambique.

Coral reefs and global change – a historical perspective spanning the western Indian Ocean (Western Indian Ocean Marine Science Association (WIOMSA) – MASMA grant)

This study proposes to examine the spatial and temporal environmental changes affecting coral reef ecosystems in the Western Indian Ocean. In this multi-disciplinary project, environmental geochemists dealing with the direct data acquisition on biological archives (corals), will work in partnership with climate scientists, environmental modellers and ecologists. This will allow direct comparison of the geochemical data obtained by the geochemist with models of river discharge and pollution and ecological changes. Integration of these data should provide a far better understanding of the entire ecosystem in the region investigated and lead to improved sustainable management of the coastal environment.

Evaluating current responses and projecting the effects of climate change on WIO coral reef ecosystems from historical environmental variability (Western Indian Ocean Marine Science Association (WIOMSA) – MASMA grant)

Projecting and predicting the future effects of climate change is the first step in preparing a response that can evaluate the potential impacts on coral reef social-ecological systems. The opportunity to improve future projections is based on the accumulating information contained in coral cores and satellite data that have been collected during the past decade, which can form a basis for determining the temporal and spatial variability and how this is likely to change in the coming years. These data can, in principle, be priors in Bayesian predictive models that can be used to make predictions on future states of the environment. Additionally, the ability to predict current temperature stresses and bleaching has improved such that the probabilities of bleaching can be predicted for certain places at periods of 2 to 3 months before the impact. The proposed work will use these sources of information to develop a map of the projected changes in environmental conditions and to undertake field research in areas prior to and after the temperature anomalies to determine the impacts of current stresses on key metrics of the coral reef ecosystem including coral health, symbionts, reproduction, recruitment, and fish populations. These two studies, when combined, can be used to parameterize an existing coral reef ecosystem model to generate projections of regional ecosystem responses to future climate change scenarios.


Ocean acidification

research locations on Ocean acidification

Potential Impacts of Higher Ocean Acidity and Warmer Water Temperatures on Abrolhos Island Coral Reefs

The broad aim of this study is to determine how high latitude corals in Western Australia (WA) will respond to climate change stressors such as warmer waters and ocean acidification.
More specifically, this study aims to determine the thermal tolerance limits and threshold saturation states for dominant hard coral species from the Abrolhos Islands, as well as to investigate the potential for their migration southwards under future climate scenarios.

Resilience of coral reef communities and coral metabolism in extreme environmental conditions

The study site will be centred around Cygnet bay in the Kimberley Region, where huge tides (up to 11.7 m tidal fluctuations), high irradiance and aerial exposure in some places, create a highly fluctuation temperature regime.
The corals are subjected to conditions that fluctuate at a rate that would normally cause corals to undergo bleaching i.e. the loss of the algae symbiont, yet these corals seem to have adapted to the extreme conditions.
In the cause of trying to unearth the cause of why these corals have this remarkable resilience; it is important first to know exactly what environmental conditions they have adapted to.

The effects of ocean acidification on calcification rates of reef-building corals and crustose coralline algae in Western Australia

The project aims to determine in situ calcification rates of corals and crustose coralline algae in both temperate and tropical coral reefs off the coast of Western Australia.
A long-term record of calcification rates under monitored environmental conditions and natural temporal and spatial variation in ocean chemistry will enhance our understanding of how key reef-building species react to environmental change, and how this response varies with latitude.