An assessment of local fisheries in Diego-Suarez Bay, Madagascar

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Identifying where the main fishing areas and areas of high fish biomass, species diversity, high numbers of fish counted and coral cover within the bay provide information for possible management schemes, in terms of implementing no-take zones. 4.3 Summary of possible conservation management methods Restricting the use of seine nets to reduce coral damage (McClanahan et al., 1996) and regulating mesh sizes to reduce juvenile mortality and by-catch could help to prevent the effects of overexploitation, by increasing juvenile survivorship (Lindholm et al., 2001). The introduction of no-take zones in areas like the eastern part of sector 4, the western part of sector 5, Nosy Koba and Nosy Langoro would encourage long-term survival of fish stocks. This would in turn help protect the spawning stock of the exploited populations, which could lead to the build up and replenishment of adjacent fishing grounds (McClanahan & Mangi, 2000; Roberts et al., 2001). The introduction of no-take zones would have to be clearly explained with examples given of how successful it can be given to the local fishermen. This is a very important point, as clear explanation would help to reassure locals who are currently against having area restricted to fishing. Workshops with the local villages that use the bay would provide education on a number of important issues that could improve the marine environment of the bay. Educating local fishermen on reducing discarded fishing gear could minimise ghost fishing and coral damage. Using divers (e.g. Frontier volunteers) to survey areas and systematically remove debris (Donohue et al, 2001) would improve the reefs ecosystems and reduce the likelihood of ghost fishing. Informing fishermen that by-catch be respected and returned to water would help to reduce the occurrence of unnecessary mortality and prevent a reduction in species diversity. Providing information on the size or age at sexual maturity would help fishermen understand the importance of not removing fish from the ecosystem before they have had the opportunity to spawn. This could in turn allow the introduction of a minimum capture size to guarantee that fishermen do not remove fish younger than spawning age. See Mangi & Roberts, 2006 for details on length at sexual maturity for coral reef fish species. With the increase in the local population of Diego-Suarez and other villages surrounding the bay plus an increase in tourism, the sustainability of the fishery will need to be controlled and regulated. The formation of a Diego-Suarez Bay fishery alliance including representatives from key stakeholders such as fishermen from each village, business / hotel owners, local government officials from Diego-Suarez and local conservation organisations such as Frontier, could form the basis for a local management strategy. The formation of such a body would be able to help manage the bays resources, taking into account the different needs of each key stakeholder, while incorporating local beliefs and fadys into management plans. 4.4 Summary of topics for future study Estimate total catch from the bay by assessing daily catch weights and species composition of catches. Compare this value with an estimate of the fishery’s productivity to give a more accurate idea of whether the fishery is currently sustainable or not. From this measures can be suggested to improve its sustainability. Assess the impacts of seine net fishing, to provide information on whether steps should be taken to regulate current activities. Assess how the growth of tourism in Ramena is affecting fishing pressure around the bay. Investigate how to provide alternative sources of protein to help reduce fishing pressure. Examine whether the current number of tourists visiting Ramena would be enough to support an increased number of tour guides as a possible alternative to fishing. Investigate the differences in fish size distributions between areas of high fishing pressure and areas of low fishing pressure to identify if fishing has an impact or not. Other factors such as access to fishing areas, reef quality and other environmental factors such as exposure and levels of sedimentation need to be considered to correctly identify the cause of the current fish size distribution. 20
5 Conclusion Prior to this research very little was known or documented about the fishery in Diego-Suarez Bay. This study has been able to assess how fishing in the bay is carried out and what potential issues the fishery faces. Much of what was found follows the template of other tropical reef fisheries around the world, including the use of traditional fishing methods and increased fishing pressure due to population expansion and local development. Diego-Suarez Bay is clearly an important and well-used resource for local villages. Fishing is the principal use of the bay and a number of issues associated with the fishery have been identified. Fishing in the bay clearly has an impact on the fish themselves, as well as on the environment. The fishery is not in a bad state although through various management strategies it could become more productive. The scope for using this study as a guide or resource for the future management of the bay is feasible. Further investigation, of which some is suggested in this study, would help to provide a greater information base to assist with the creation of suitable and accurate management strategies. 21
Page 1: Frontier Madagascar Environmental R
Page 4 and 5: Suggested Technical Paper citation:
Page 6 and 7: ACKNOWLEDGEMENTS This report is the
Page 8 and 9: EXECUTIVE SUMMARY The artisanal fis
Page 10 and 11: 2 Methods and Materials 2.1 Survey
Page 12 and 13: 3 Results 3.1 Socio-economic data P
Page 14 and 15: ut the majority of fishermen do not
Page 16 and 17: Table 3. Fishermen’s opinion on r
Page 18 and 19: Mean number of fish 14 12 10 8 6 4
Page 20 and 21: either poisonous to eat (in the cas
Page 22 and 23: 4 Discussion 4.1 Socio-economic and
Page 24 and 25: elieved that the size has decreased
Page 28 and 29: 6 References Adam, M.S., Anderson,
Page 30 and 31: Appendices Sample Questionnaire Fis

An assessment of local fisheries in Diego-Suarez Bay, Madagascar

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