Madagascar mapping, interviews, and deployed dugong detectors – much success and a few setbacks
August 22, 2016
MG6 Project Update: Jan thru June 2016
This period represented the start of the monitoring phase of the project. Activities included seagrass mapping, completion of the community interview surveys in the northern portion of the study area and deployment of acoustic loggers. The project is implemented by WCS covering two MPAs – Ankivonjy (139,409 hectares), located in District Ambanja, Region Diana and Ankarea (135,556 hectares), located in District Ambilobe; Region Diana
After the seagrass ground truth surveys were carried out in the northern portion of the study area in November 2015, maps for this region were finalised and submitted to the PCT.
126 community interviews in 42 villages were carried out in March 2016. In a number of villages the interview allowed for identifying the dugong hunters, although no active hunts were revealed. There were three villages, for which records of dugong sightings were the most promising.
The majority of dugong sightings generally occurred from July to September and sightings or catches were in low numbers or none in most years, with the highest number of dugong catches recorded for 2014 (4 dugongs caught in nets).
The interview survey results, combined with the seagrass mapping, were used to choose two separate areas to focus the deployment of acoustic loggers – inland from Nosy Komba and Ambaro Bay.
Six acoustic loggers were deployed in April 2016 (three loggers deployed at each site) in areas adjacent to seagrass beds where water depth was sufficient to prevent the loggers being exposed during low tide (between 5 to 9 meters – low tide).
Given the high number of artisanal fisherman in both locations, there was concern that the loggers may be stolen or tangled in the fisherman’s gear. To mitigate against these issues, the loggers were deployed with a subsurface float and heavy anchor system (20kg concrete blocks), so that they would not be visible at the surface and would not be easily dragged. The loggers were also labeled carefully with WCS contact details in case they were tangled in the fisherman’s nets and removed by the fisherman. Additionally, before deployment, local communities were alerted of the deployments (although not the exact location) in the hopes that they would leave the recorders if they saw them or contact WCS if they became entangled in their nets.
However,
three of the loggers were lost assumed to be due to entanglement in fishing nets. Despite all efforts of the WCS’s team to find and get back the devices, the loggers were not found.
The team decided to not deploy further devices in Ambaro Bay, also because of the low water visibility and to postpone the deployment of the devices in Nosy Komba, until getting the support of the local fisherman communities. The potential solutions were discussed with the PCT, who also posted an SOS message on the global Project website and Facebook.