Hard corals are the key ecosystem architects on coral reefs and produce a physical complexity that provides habitat for associated reef fish species. One of the effects being noted around the world due to increased storm damage or destructive fishing techniques such as bomb fishing, is a decline in this physical complexity which then will have negative consequences for associated fish communities. Until recently, physical complexity of reefs was measured using a basic technique known as chain-and-tape, whereby a chain is laid across the surface of the reef to give a simple rugosity value. This crude method is limited in its accuracy, and can even cause damage to the reef itself. An alternative method uses diver observations to assign a complexity score based on set criteria; this method is known as the Habitat Assessment Score (HAS), but is subjective and can also lack accuracy. More recently, advances in underwater videography and computing have led to the development of 3D modelling as a tool for accurately quantifying reef complexity. Opwall scientists have developed their own 3D modelling approach that uses structure-from-motion photogrammetry applied to video footage from underwater cameras, and in 2020 this method will be launched at our Indonesia site in conjunction with our fish and benthic survey teams. Students on this project will film different areas of reef across multiple sites, and construct 3D models from the footage. Analysis of these models will give accurate measurements of structural complexity, and these can be compared to data on fish community structure and benthic reef health to explore fine-scale patterns in the importance of complexity as a driver of reef biodiversity.
If you would like to do a dissertation or thesis with us but your university hasn’t started dissertation planning or the project selection process, that’s no problem. You can cancel your expedition with zero cancellation charges up until the 15th of April of if you provide documentation from your university saying that they won’t support completing a dissertation project with us.
There is a triangle of reefs in Eastern Indonesia that have the highest diversity of hard coral genera, the proxy commonly used to assess overall diversity of coral reefs, anywhere in the world. Both the marine stations being used by the Opwall teams are in the centre of this triangle. The South Buton Marine Centre has established a series of standard monitoring sites on reefs south of Bau Bau and around the surrounding small islands, with the objective being to use the data to develop plans for conserving these reefs. The Hoga Island Marine Station is located in the heart of the Wakatobi Marine National Park. Over the last 20 years, a series of scientists have been based at this site during the Opwall survey seasons and as a result, this is now the most published site in the Coral Triangle. For the last 15 years a series of constant monitoring sites around Hoga and eastern Kaledupa have been monitored for macroinvertebrates, fish communities, coral cover and community structure. The 2020 season will complete this monitoring plus some additional projects.
At the marine sites during the day, the weather is normally sunny and warm (around 30 degrees Celsius), and the night temperatures drop to around 20-25 degrees Celsius. Being on the coast means there is often a pleasant breeze so it does not always feel this hot. It rains rarely, but when it does it tends to be very heavy for short periods of time.
Fitness level required
Low-Moderate. Some fitness is required for in water activities, but conditions are relatively easy.
The Hoga Island Marine Station is an established facility that lies within the Wakatobi Marine Park of eastern Indonesia. The station was rebuilt in 2016 and supports a dive centre, lecture theatre, wet-lab as well as a large dining room and kitchen facility. Simple huts owned by members of the local fishing community surround the station and serve as guest accommodation. The island supports reliable phone signal that allows limited internet access.