This topic utilises the stereo video and quadrat photographic data gathered by the Operation Wallacea teams on reefs in southern Mozambique in 2009 and 2010 and which will be repeated in 2011. Software is available in camp to identify each fish species recorded along the stereo video transects and to measure their fork length accurately. There is also software on site, which can be used to accurately record the total area occupied by each coral community on the digital photos. The data set would consist of replicate transects surveyed at different depths on a series of reefs in 2009 2010 and 2011 and image analysis could be completed for total coral cover, hard and soft coral communities and reef fish communities and size groups to quantify changes that had occurred between the years. The data from this topic could also be analysed to assess the relative effectiveness of utilising different length transects, how coral cover, coral communities or fish communities and size groups change with depth. For those students at universities where completion of their dissertation/thesis outside of term time is not allowed, this topic provides an opportunity to gain experience in conducting fieldwork and a guaranteed data set for later analysis.

Download the reading list

MM205 The influence of depth as a refuge from fishing pressure on reef fish communities
(weeks 4 - 10; need to have completed MM005 and be dive trained or have completed MM004).

On coral reefs, the distribution of fish is related to numerous factors such as depth. habitat and fishing. Recently, on coral reefs of Zanzibar, depth was shown by researchers to play an important role as a refuge for fishes against artisanal fishing pressure. On southern Mozambique reefs, aritsanal fishing is low to nil, and fishing pressure is largely from the recreational sector. Previous researchers in other parts of Mozambique have suggested that artisanal fishing gear, mainly seine nets, traps. handlines and spear guns, are only able to fish relatively shallow water. In contrast, the recreational fishing gear, mainly handlines, used on southern Mozambique reefs can fish most depths. While it is illegal there to bottom fish on reefs, lost fishing gear from 'snagging' and fish hooks present in the mouths of larger carnivores such as Epinephelus tukula  (the large Potato Cod) are frequently sighted, indicating that bottom fishing on reefs still occurs. This topic will utilise the stereo-video survey technique to sample diversity, abundance and length of reef fish at various depths on southern Mozambique reefs. These data can then be used to test hypothesis that depth will act as a refuge for fish communities where high diversity, abundance and potentially larger fish also occurs on southern Mozambique reefs.

Download the reading list

MM206 Indicator species of hard coral cover on southern Mozambique reefs
(weeks 4 - 10; need to have completed MM005 and be dive trained or have completed MM004).

It has long been shown that proxies can be used to indicate the relative health of other taxa, and on coral reefs the fish family Chaetodontidae (Butterflyfish) is often used as an indicator of hard coral cover and health. Chaetodontids are generally obligate coralivores (with some being omnivores) and their diversity and abundance increases with increasing hard coral cover. Nineteen species of chaetodontids are found on southern Mozambique reefs. The first question that can be asked is whether the diversity and abundance of chaetodontids can be correlated with the percentage cover of hard coral. If a correlation can be established, this will allow completion of Butterflyfish surveys as a proxy for reef health. A gradient of coral cover can be detected from the reefs adjacent to the camp, towards those further north. Also occurring along this spatial scale is a gradient of human impact from SCUBA diving. Coral damage is well documented on reefs where divers frequent, and in this region most diving occurs around Ponto Malongane and Ponto do Ouro, with diver frequency decreasing towards the north.

Download the reading list