Since 2005, FMMRP has compiled three years worth of marine ecological data. This includes Baseline Survey Protocol (BSP) data relating to benthic community composition, the abundance and structure of fish populations, the abundance of key algae and invertebrate species and physical reef characteristics. These datasets have aided in the creation of a baseline from which temporal monitoring of the Bay ecology can be conducted.
The FMMRP 2008 Technical Report (Report 25: An Assessment of Coral Reefs and Mangroves in the Bay of Antsiranana) aims to analyze and summarize the research carried out during 2008 in order to provide an accurate picture of the state of Antsiranana Bay in this period. This is mainly done through the analysis of benthic data and the variations this data shows between coral and substrate cover as a key indicator of reef health.
The key findings for the BSP data collection were that hard coral made up the highest benthic coverage across all the surveyed sites and throughout the year, although the level of hard coral cover was significantly different between sites. Rock, rubble and sand were more prevalent within the benthos than recently killed coral, sponges or seagrass, although sediment coverage was significantly higher during the April – June research period. Soft coral was present at all sites and remained relatively constant throughout the year.
There was no significant variation in algal cover between areas or research periods, although algal diversity varied significantly both temporally and spatially, potentially as the result of environmental and seasonal variations. The abundances and diversity of invertebrate species varied significantly between research sectors, suggesting the need for future investigations into the potential impact of invertebrate harvesting by local communities on invertebrate populations.
In addition to BSP data collection, FMMRP also began an investigation into the condition of mangrove stands within the Bay’s intertidal zone. Despite providing a number of important ecological services, Antsiranana Bay’s mangroves have been heavily depleted in recent years, and have been identified by Frontier as a key area for conservation efforts.
Throughout the 2008 research phases, mangrove surveys were conducted at four research sites around the bay. For each stand, species present, species abundances, dominant species and biomass were recorded. The results showed a dominance of Rhizophora and Ceriops spp. across the survey sites, with species diversity increasing towards the mouth of the bay. Further study of mangrove stands and socio-economic survey work is required in order to assess the impact of local communities using mangroves as an extractive resource in order to fully understand the impact of mangrove use in the Bay.
Overall, the BSP data collected in 2008 suggests that the bay is in a relatively good state of health, although the research could benefit from further study, with a particular focus on invertebrates. The mangrove project has acted as a good pilot study, but a lack of past data makes it difficult to draw strong conclusions at present. Further research is required before work can begin on an effective mangrove management strategy.
For more information, or to get involved with Frontier’s Madagascar Marine Project, please visit the Frontier website (http://www.frontier.ac.uk) to find out about volunteer abroad opportunities
Tags: bay ecology, community composition, coral reefs, fish populations, invertebrate populations, reef health, research periods, research sectors, rock rubble, survey protocol