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

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4 Discussion 4.1 Socio-economic and visual observations Diego-Suarez Bay is an important resource for many villages and local people who rely on it for many uses. The results from this study show that fishing and subsistence are the two main interests local fishermen have in the bay (figure 2). Due to the poorly maintained roads, mainly consisting of unpaved dirt tracks that surround the bay, the water is an important means of transport and provides local villages with their principal method of travel. This allows villagers and fishermen alike to travel to and from villages surrounding the bay as well as to the main ports of Diego-Suarez. Interestingly conservation was mentioned as an interest by a small minority of fishermen, who believe that conserving the bay’s resources particularly fish is important for future generations. The extent of the environmental awareness of the fishermen will be discussed later in this section. The fish or invertebrates targeted by fishermen ranged considerably. Some fishermen targeted only single families such as snapper or tuna or octopus, however the majority of fishermen chose to target multiple families (figure 3). This is characteristic of reef fisheries across the world where the assemblages over reefs contain a variety of families (Choat & Robertson, 2002). The number of edible species found on and around reefs is high and with such abundant numbers and diversity of edible fish, fishermen concentrate fishing effort around these areas. The most popular families that are targeted are Carangidae (Jacks), Lutjanidae and Mullidae. Fishermen in Diego-Suarez target these families mainly due to how common they are and therefore most likely to catch (figure 4). The income they bring the fishermen is also important and in the case of jacks they fetch the highest price at the market (table 4). Fishermen also target certain fish, as they know where the best places are to catch them and what the best methods are to use. Knowledge passed down from generation to generation helps fishermen to increase their success rates. Fishing equipment can determine what species they catch, as different types of gears used can target different families of fish. Hook and line method will target mainly resident families such as Haemulidae and Serranidae, where as gill nets target transitory or schooling families such as Siganidae, Carangidae and Lethrinidae. Seine nets are largely unselective in what families they target, catching what ever is in the way. Spear guns in contrast are highly selective as they are used to catch whatever the fisherman wants. The majority of the equipment used are hook and line and gill nets, of which both were used by 70% of the fishermen interviewed (figure 5). Fishermen from Antsisikala primarily used these methods. The catch-per-unit effort for hook and line ranged from 0.3 – 7.5 kg person -1 hr -1 . The maximum value was given by fishermen targeting tuna who could catch one or two large fish in a day using a hook and line. The type of fishing observed by fishermen using these methods was small-scale fishing typical of reef fisheries. Enough fish would be caught to provide for a family or village, with any excess being sold. Calculating the total catch from the bay and comparing it to the estimated productivity is needed to give a more accurate idea of whether the fishery is currently sustainable or not. Seine nets and traps are used significantly more frequently in Ramena than outside. As Ramena is primarily a fishing village (although now becoming a popular tourist resort) with a beach extending approximately 4km in length, using the seine net is a labour intensive yet viable option as the local labour force is skilled and experienced in using this technique. The high fishing effort involved, in some instances will provide enough fish for the labourers, plus extra to sell if required. It therefore can be highly profitable in terms of catch-per-unit effort, with a maximum of 3.1 kg person -1 hr -1 being identified in this study. Interestingly this was a very community driven practice with people (both male and female) who were not part of the fishing group helping out if the size of the catch required it. Those who helped would receive a small bag of fish as a reward for their efforts. No destructive techniques are used such as poison or blasting fishing. The lack of any destructive techniques being used in Diego-Suarez Bay indicates that fishermen have a respect for the conservation of resources and that fish can be exploited generation after general if their habitats are not destroyed. It also means that the fishermen believe in their own skills and the techniques they use, without having to change their methods to less skilled and non-specific methods such as poison or dynamite. A view of “if the fish 16
don’t bite today then tomorrow will be better” was commonly mentioned while talking to fishermen. According to fishermen, techniques have not changed in the time they have been fishing. What has changed is the gear material. Nylon fishing line and nets are commonly used, as they are lighter, more durable and less visible to the fish than traditional natural materials. Although the methods have not changed the fishing methods have become more effective and will catch a greater proportion of the available fish. Therefore even if fish stocks are declining, catch sizes might stay the same or even increase. This will only exacerbate the decrease in fish stocks. Unfortunately the other negative aspect of using modern material is that they persist in the environment if discarded and are a common cause of ghost fishing (see Matsuoka et al., 2005). Fishing practices in the bay are impacted by the weather conditions during the year, with more fishing being conducted during the rainy season (November to March) when sea conditions are calm. During the windy season many fishermen head to the Mozambique Channel where conditions are more favourable. If conditions are favourable then fishing will occur each day of the week for the whole week. The time spent by fishermen out on their boats ranged from 1-12 hours, while the mode was 4 hours, indicating fishing practices are mostly fisher specific. The fishery has very little wastage, with fish being thrown back primarily if they are too small, while only some fishermen will throw them back if they are not the target species or not valuable (figure 6). Most fishermen will keep whatever they catch regardless of size or type and even if they are not good to eat (poisonous fish are discarded). Those using beach seine nets were observed sorting the catch on the sand into fish type and discarding non-edible or poisonous fish. Discarded individuals, most commonly puffer fish and trunkfish, were left on the sand and not returned to the water. The lack of selectivity of this method was clearly identified catching a mix of reef, seagrass and reef-associated fish. Although fishermen stated in their questionnaires that any non-target fish where returned to the water the contrary was observed in some cases. A lack of knowledge or understanding persists that, although some fish are not edible , there is still an ecological importance in returning them to water to rejoin the reef ecosystem. Education through workshops would be an applicable management strategy to inform fishermen that bycatch be respected and returned to water. One observed catch saw around 50 kilos of sardines landed amongst other by-catch fish, which was considered to be an excellent catch. If locals were more selective in when they cast their nets and only targeting large schools of fish such as sardines, then the by-catch of reef species could be dramatically reduced. Limited environmental education workshops have been carried out around the bay (Frontier Madagascar 2007), but there is need for a more sustained approach. Fishermen using single person pirogues tended to be fishing for subsistence rather than commercial purposes, using the hook and line method or a small net. These two methods as well as traps and spear guns do not yield an excessive amount of fish, as most fishermen using these techniques had an average catch weight of 1-24kg. In contrast fishermen from Ramena have heavier catches than those fishermen from Antsisikala as a result of using seine nets. The catch was divided amongst the fishermen for their own consumption, with a small proportion being sold to the local restaurants. Catches in general were sold depending on the size of the catch, although some fishermen chose to sell every few days. If their catches were large or they catch some large fish then they will sell them at the market or to restaurants in Diego-Suarez. With an increase in tourism in Ramena, an increasing amount of fish is being caught and sold on to the local restaurants. This study does not go into any detail on how the growth of tourism in Ramena is affecting fishing pressure around the bay. This could be a possible line of enquiry for the future. There was no universal reason given by the fishermen on why they thought that catch size and abundance had decreased during their time fishing (table 1). Many answers were given, with more fishermen fishing than before (the highest response) and the effects of climate change being the most popular (table 2). It is not clear whether they fully understand how climate change could be the cause, or whether they are just using it as a scapegoat. Local opinion is that more young men are becoming fishermen as they see this as a better option than farming. This may explain why there are more fishermen being observed fishing. Fishermen may also be travelling further in search of new or better fishing grounds and entering areas that they would not commonly fish in. However, the most likely cause is population increase. The size of fish has stayed the same according to the majority of people interviewed, however a large number also 17
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 24 and 25: elieved that the size has decreased
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

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