There are reports from across the world of coral regime shifts, whereby declines in coral result in increased abundance of other benthic groups. Throughout the Caribbean these changes are typically to reefs dominated by algae, but in the Indo-Pacific changes to reefs dominated by other animal groups are more common. In the last few years there has been particular interest in the sponges as these are one group of organisms that have been identified as potential ‘winners’ in the face of environmental degradation and climate change. Within the Wakatobi a transition has occurred on one major reef system, Sampela, where coral abundance has declined over the last 10 years to very low levels, but sponge abundance appears to be increasing. In particular, this site is dominated by the giant barrel sponge, Xestospongia spp. and the encrusting sponge, Lamellodysidea herbacea; these have also been reported as increasing in abundance in other parts of the Indo-Pacific. In addition, recent experimental evidence has shown that sponges appear much more resilient to ocean warming and acidification than coral, so are likely to be a greater feature of coral reefs in the future. Dissertations in this area will build on long term datasets to track this shift in dominance and explore the ecosystem level effects. Projects might also include behaviour based studies to understand levels of spongivory and which species of reef fish are able to utilise sponges as a food source. Further studies should examine the competitive interactions between corals and sponges, the later being known to utilise a number of competitive techniques including direct overgrowing as well as chemical attack. Therefore research could also utilise an experimental approach to examine implications of sponge-derived chemicals for coral productivity. It is undoubtedly the case that greater effort is needed to understand the interactions between corals and sponge and the consequences of sponge dominated systems for coral reef biodiversity. Research activity will also allow us to explore the potential management interventions needed to prevent future regime shifts.
There is a triangle of reefs in eastern Indonesia, part of which lies within the Wallacea region, that have the highest diversity of hard coral genera in the world. This proxy is commonly used to assess overall diversity of coral reefs and is an indication of high species diversity in other taxa such as fish and large marine mammals. Both the marine research stations being used by the Opwall teams are in the centre of this triangle.
The South Buton marine research centre opened in 2013 and has established a series of standard monitoring sites on reefs south of Bau Bau and around the adjacent islands. These are being monitored annually and it is hoped to use the data to demonstrate that a number of the reefs in this area are of high conservation value. Preliminary social studies have commenced as of 2017, involving interviewing fishermen and other local stakeholders to gauge areas of high fishing pressure and the preferred catch methods. The next step is then to begin implementing some conservation management strategies involving all of the local stakeholders in the near future. There is also a small team at this site working in collaboration with the Global Fin Print Project, which monitors shark and ray populations through the use of baited remote underwater video systems.
The Hoga Island marine research 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 have built up the publications emanating from the site to a level which is unsurpassed by any other marine research site in the Coral Triangle. These data and publications have been used to promote the biodiversity value of the Wakatobi, raise its profile internationally and in particular enable it to be designated as a Biosphere Reserve. For the last 12 years a series of constant monitoring sites around Hoga and eastern Kaledupa have been monitored for fish communities, coral cover and community structure and macro-invertebrates. In addition annual fisheries monitoring is being completed to assess changes in the fisheries particularly as some of the management initiatives developed by Opwall (e.g. buy outs of fishing licences and carrageenan extraction) begin to hopefully have an impact. Alongside these long-term monitoring projects there are also newer projects such as a coral restoration program and seagrass monitoring to provide a wide range of opportunities to all.