Today we will dive into the experience of the ARMS Restore project research team members in the “Fisheries and Fish Diversity” component. A fisheries survey was conducted over 15 months (from October 2021 to January 2023) throughout 12 villages of the Bay, involving 103 fishers and local communities. The survey includes four components: (i) participatory survey of daily catch, (ii) boat trajectory survey, (iii) monthly landing survey for catch diversity, and (iv) study of the sexual maturity of reef fishes. This collaborative research is a partnership between Fisheries and Marine Sciences Institute, University of Toliara (IH.SM), French National Institute for Sustainable Development (IRD) via the MIKAROKA international research laboratory and the NGO Reef Doctor. The team is composed of two PhD students (Sandra Ranaivomanana in Fisheries and Anissa Volanandiana in Fish Diversity), two research assistants in Fisheries from IH.SM and two fisheries technicians from Reef Doctor.
For the data collection, innovative methods and tools were used, such as GPS trackers to determine fishing area location and habitat exploited, photographic device and software to identify and measure fishes and DNA barcoding for a precise identification of exploited diversity. For a given fisher sampled and surveyed, the GPS devices are carried by fishers on their traditional pirogues for each fishing trip. The weight of daily catch and other information related to fishing activity was recorded on sheet form during the 30 days of survey (e.g. gear type used, number of fishers on-board, the fishing area, price of product). Then, once per month, the catches are weighed and photographed. Some samples have been used for DNA barcoding and to study the sexual maturity of the fish through a dissection to obtain the proportion of adult and juvenile fishes in the catches.
To date, 80,000 fishing trips were recorded and around 1,000 landing surveys were sampled. Catches in the bay are composed of 66 families of reef fishes. The DNA barcoding is currently in process in the laboratory of the University of Montpellier, France in order to obtain the list of species caught. Fish measurement and data analysis on size at first maturity are also in progress. In March 2023, fisheries monitoring continued and transferred to Reef Doctor staff under the supervision of the “Fisheries and Fish Diversity” team.
All data collected during this survey will be used as an indicator of the fisheries pressure and impact to assess the fishery status in the Bay of Ranobe. This kind of collaborative research will improve monitoring of the fishery, community awareness, and commitment to regulated fishing practices, and ultimately contribute to improved resource management and socio-economic outcomes for fishing communities.