Outbreaks of crown-of-thorns starfish (COTS) are the second most significant cause (after tropical cyclones) of the long-term decline in coral cover (1986-2011) on reefs adjacent to the developed coast of Queensland. The control of COTS has until recently been done through lethal injections of sodium bisulphate (Na(SO4)2).
For this chemical to be lethal, it is necessary to inject each starfish in multiple places with very large animals requiring as many as 28 separate injections. This requires the starfish to be removed from the coral for proper access to all injection points.
The limitations of this technique include the large volume of salt solution needed to be carried by each SCUBA diver and the time it takes to access and inject each starfish multiple times. The use of bile salts (sodium cholate C24H39NaO5 (NaC); sodium deoxycholate C24H39NaO4 (NaD)) has been found to potentially improve the efficiency of the injection method. Aquarium and small scale field trials have shown that this method requires only a single injection per starfish.
Despite extensive aquarium and small scale controlled field trials to ensure the biosafety of this new method, it required a proper, full scale field trial to include aspects such as large aggregations of dying starfish, and simple operational safety before it would be permitted as an acceptable COTS control method.
I was the project manager, dive and cruise leader for this project. To ensure the outcomes were based on realistic and reliable scenarios, the project was set up along the lines of a before and after impact survey to detect possible changes or significant differences between controlled and non-controlled areas. Four reefs were surveyed, one control site and three injection sites.
Concentrated aggregations of COTS were generated on one of the three injection sites to control for the potential adverse effects of large numbers of COTS dying in a small area. Each survey included starfish counts at three spatial scales. Large transect counts encompassed four 5 m x 50 m belt transects at each site. Small transects counts (four 1 m x 50 m belt transects) focused more on the smaller, coral associated fish and two hectare counts were conducted at three time points at each site.
These counts covered an approximately 250 x 40 m area centred on the four belt transects that was searched along two parallel 250 x 20 m swathes. These hectare counts only recorded species that reached a length over 300 mm as adults but did not record any individuals that were less than 200 mm long, even for the targeted species. Benthic community assessments were also implemented at three spatial scales.
At each site, line intercept transects (LIT) of benthic communities were completed along the first 20 m of each of the four transects. Larger macro invertebrates were surveyed along four 5 m x 50 m belt transects and smaller macro invertebrates (e.g. Drupella) were surveyed in four 1 m x 50 m belt transects. Presence and nature of coral lesions, damage or disease were counted along four 2 m x 20m belt transects/site. There were no signs of adverse effects of the use of the new chemicals and this new method has significantly improved the efficiency of the COTS control program on the GBR.
The Great Barrier Reef Ocean Observing System (GBROOS) is the world's first reef-based IP data network, giving researchers an unprecedented range of data on reef conditions and enabling them to better track changes and impacts. Part of this network is the FAIMMS sensor network, which is an array of small, wirelessly interconnected sensors that stream data to a central aggregation point.
The sensors are ‘smart' in that they can change the way they sample depending on environmental conditions, such as sampling more often when the temperature gets above a pre-set level. Initially, they are being deployed in a large scale pilot to collect data related to the interaction of heat and light in coral bleaching, and to understanding the impact of up-welling from the Coral Sea.
The permanent moorings give information about the water column and are used to study the movement of water along the reef and any up-welling of water from the open ocean onto the continental shelf. GBROOS has four pairs of moorings located north-south between Lizard Island and Heron Island. Each pair has one off-shore deep mooring and one near-shore shallow mooring to allow the detection of water moving up and onto the reef shelf.
I have been involved in two maintenance trips for these moorings where my duties included changing moorings and chains, replacing sensors and deploying new infrastructure where needed.
I have led numerous reef trips to collect samples for my own as well as other people’s research projects.
These trips included extensive diving, recognition of coral species, field sampling and storage techniques including the handling of Liquid Nitrogen and the consideration, organisation and coordination of several research teams.
I spent 2 years working with the Koala Study Group at the University of Queensland. During that time I used radio telemetry to assess habitat utilisation of Koalas and to assess the impacts of mining and major road construction.
The data on feeding and roosting habits of Koalas was used to inform mine rehabilitation projects and fauna passage solutions over main roads.
Through this project I gained thorough knowledge of fauna and flora surveys, remote location field work, how to work at mine sites and among major projects.
