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

More documents

Recommendations

Info

elieved that the size has decreased over time. The latter view would agree with the general opinion that catch size and abundance are decreasing. Either answer is acceptable, as there will be some fish caught before they grow to a large size as a result of increased fishing pressure. There will also be some individuals that are able to reach their full adult size before being caught. With a 3.2% yearly increase in the population of Madagascar in general (Billé et al., 2002), plus an increase in visiting tourists as Diego- Suarez and Ramena become more developed, has caused an increase in fishing pressure. This study presents no direct evidence of this, however this phenomenon is well documented by fisheries scientists globally (e.g. Gedamke et al., 2007). Diego-Suarez Bay will be no exception. A rise in fishing pressure presents a significant management issue, which should be addressed to ensure fish populations are safe guarded for future generations. When questioning the opinions of the fishermen on resource use some interesting answers appeared (table 3). No areas should be restricted to fishing, according to the majority. They believe that they have the right to fish wherever they want. This view shows that fishermen would show resistance to any such management plan restricting where they could and could not fish, such as implementing no-take zones. The level of environmental awareness was high for most fishermen, showing considerable future thought for the resources in Diego-Suarez Bay. Most agreed to using larger nets to prevent catching smaller fish. This shows an understanding that by not catching smaller fish, more will grow to sexual maturity and input back into the population. Similarly catching only large fish will guarantee that they will of a large enough size to have reached sexual maturity and again would have spawned contributing to future stock (Mangi & Roberts, 2006; Grandcourt et al, 2006). Some fishermen believed targeting species because they are large spawners, or targeting one or two species only allowing others to thrive, would have a benefit on fish stocks. This would be correct, however this may have a detrimental effect on the species being isolated for targeting (Koslow et al., 1994). In reality this would be difficult to implement as a management strategy due to nature of a reef fishery, where species are often caught that are not directly targeted. Local fishermen still believe that praying to or asking ancestors will improve fish stocks. This view is predominately from the older generations who still believe that it will have an effect. Very high percentages of fishermen agreed that deforestation should be stopped in coastal areas. This demonstrates an awareness of the problems caused by deforestation such as surface run-off and its knock-on effect to nearby coral reef habitats (e.g. reef sedimentation). Agreeing with the problem could therefore signal the cooperation of villages to stop deforestation from taking place. By agreeing to only go out fishing on certain days shows that by limiting the number of days this will limit fishing effort, which therefore could act as a management strategy toward conserving fish. The majority of fishermen showing that they have a basic understanding of environmental issues is a comforting thought. Future management therefore has less risk of being dismissed and would have a good chance of succeeding, if the reasons behind the any management regulations where explained in detail. Whatever happens in the future, communities must work together on any resource use issues. Other management methods such as getting Diego-Suarez government or village chief to regulate fishing activity were agreed with by the majority. A majority also thought that individual fishermen have the right to set their own quotas. This is slightly contradictory. Its does however suggest that they would welcome some assistance in managing fishing in the bay. Eating less fish could be a viable option as a management strategy, however caution would have to be taken when implementing it, in order to provide an alternative source of protein for local people. Zebu farming could be encouraged as an alternative, although this would have to be managed carefully as to not damage surrounding areas. Seafood is important to the Malagasy people both nutritionally and culturally, so any management proposal reducing the consumption of fish may be difficult to implement in reality. A more feasible solution would be to try to increase the number of fish in the bay rather than reducing consumption. The introduction of three or four no-take zones within the bay, in areas such as the eastern part of sector 4, the western part of sector 5, Nosy Koba and Nosy Langoro would help to facilitate this. The introduction of no-take zones is well known to protect fish stocks and natural habitats, allowing fish populations to increase in density and abundance (Ashworth & Ormond, 2005; McClanahan & Mangi, 2000; Roberts et al., 2001). Increasing the number of tourists in the bay was agreed with by many of the fishermen from Antsisikala who see how people in Ramena benefit from the presence of tourists. They make money on tourist excursions, as well as selling catches to restaurants and hotels. This 18
would be a viable management option if the excursions were controlled and any environmental impacts from an increase in tourism were considered and avoided. Further investigation would have to be conducted to assess whether the current number of tourists visiting Ramena would be enough to support an increased number of tour guides. Fishing was considered to have an impact on the environment by the greater part of fishermen interviewed. Impacts witnessed during LIT and UVC surveys included; discarded nets attached to coral colonies, particularly branching and foliose species and in some cases covering about 5m of coral, discarded fishing hook and line, including one incident of ghost fishing and anchor damage to hard and soft corals. Most of the study sites exhibited some visible impact to fishing. Education through workshops providing information on how to reduce impacts would be a simple management plan to reduce damage. Local Malagasy people observe fadys, which are acts of taboo or banned activities due to superstitious beliefs. Many fishermen consider there to be fadys associated with fishing. There are a number of local fadys described by the fishermen which would fit in well with management schemes e.g. no fishing at night, not using lights at night, no banging the water, no fishing on Tuesdays, Thursdays and Sundays, and not using metal in the water. These local customs could be combined with other management schemes to provide a management plan that is considered acceptable by all local people. The questionnaire results provide an interesting insight into the opinions of the fishermen. As with the use of questionnaires in general in scientific investigations there is always an element of the interviewee saying things to please the intervie wer. Due to the questionnaires being conducted through an interpreter it is difficult in this case to determine whether the interviewees were saying this they considered the interviewers wanted to hear. However each interview was done separately to prevent the interviewee having their answers being influenced by others. The fishermen interviewed were very welcoming, were not distrusting of the questionnaire process and thus we feel that the results are unbiased. 4.2 Resource status (UVC and LIT) and visual observations A number of relationships were tested to determine if there is a pattern in the biological value of sectors and the presence of fishermen. No association was found between hard coral cover and number of fishing vessels (figure 8), fish species richness vs. number of fishing vessels and mean number of fish counted vs. number of fishing vessels. There was however an association between mean fish biomass vs. number of fishing vessels (figure 9). Fishermen appear not to be visiting areas where there is high coral cover, high fish species richness and high fish counts for their chosen areas to fish. Fishermen are fishing areas where they know there to be a large biomass of fish. How they know this is likely to be through knowledge passed down from generation on where to find the largest resident fish or where to follow seasonal migrations of reef associated fish. Personal experience and observations over many years of fishing would also give them the knowledge on where best to fish. The mean size of fish found in the bay regardless of species shows that there is a distinct lack of fish larger than 30cm in length (figure 10). Fishing pressure is likely to have caused this, as all of the reefs in the bay are easily accessible, fringing reefs. Being able to compare fish size with offshore reefs or barrier reefs (such as in Nosy Be, northwest Madagascar) that are more difficult to access could prove that fishing pressure is the cause of a reduced numbers of fish >30cm and not any other anthropogenic or physical factors. The fact that fishermen are able to travel relatively short distances, fish and then camp on the nearby shore, allows them more time to fish compared to fishing in the open sea and returning to land each day. It also allows them to move to a different area if they are not having success. This means areas can be fished by different fishermen several times a day, increasing fishing pressure. The ease of access of these reefs could be a confounding reason to the high and continuous fishing pressure. Investigating the differences in size distributions in areas that have no fishing pressure with areas having varying degrees of fishing pressure to identify if fishing has an impact or not, would be a key line of enquiry for the future. Taking into account access to a fishing area, reef quality and other environmental factors such as exposure and levels of sedimentation would help to provide accurate results. 19
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 26 and 27: Identifying where the main fishing
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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?