Rural livelihoods and mangrove degradation in south-west Madagascar: lime production as an emerging threat
I VAN R. SCALES,DANIEL A. FRIESS L EAH G LASS and L ALAO R AVAOARINOROTSIHOARANA
Abstract Mangroves are heavily threatened globally, with Introduction fuelwood harvesting and charcoal production a growing threat in low-income nations. However, the socio-ecological lobally, mangrove ecosystems are heavily threatened dynamics of mangroves are poorly understood, especially G(Duke et al., ). Although aquaculture has been the roles of poverty and wealth in shaping resource use. the biggest proximate driver of mangrove loss in many re- This is particularly the case with Madagascar’s mangroves, gions (Walters et al., ; Richards & Friess, ), harvest- which contribute % of global mangrove cover. We report ing of mangroves for fuelwood and charcoal production is a on the use of and threats to mangroves in the Bay of growing threat in low-income nations (UNEP, ). Assassins in south-west Madagascar. We document the Deforestation and degradation of mangroves have serious production of sokay, a sea-shell based lime produced in socio-economic implications linked to the loss of important mangrove wood kilns and used as a render on houses to im- ecosystem services, including the provision of building ma- prove their durability. Lime rendered houses are considered terials, fuelwood, charcoal, fish and shellfish (Walters et al., a status symbol. Growth in the use of lime is related to a rise ; Barbier et al., ). Other services include storm pro- in income in some households, which is partly a result of the tection, carbon storage and a range of cultural services increased commodification of marine products such as (Barbier et al., ; Costanza et al., ). octopus, seaweed and sea cucumber. These products have Despite their importance, the socio-ecological dynamics experienced rapid commercialization over the last decade, of mangroves are poorly understood (Bandaranayake, ; ’ with fishers now supplying global markets. We also docu- Walters et al., ). Madagascar s mangrove ecosystems, ment evidence of the emergence of larger-scale lime produc- which make up % of global cover, remain particularly tion. The growth of lime production has major ramifications understudied (Giri & Muhlhausen, ; Harris, ). for mangrove cover. We have observed a worrying develop- They are increasingly threatened by conversion to agricul- ment in mangrove harvesting patterns tied to lime produc- ture and charcoal production (Giri & Muhlhausen, ; tion, where mangrove ecosystems are cleared instead of Jones et al., ), although there are considerable geograph- selectively cut. We consider the implications of our findings ical variations in socio-ecological dynamics (Jones et al., for broader debates about the relationship between conser- ). Given the central role mangroves play in the liveli- vation, poverty and natural resource use. We highlight re- hoods of many coastal communities in Madagascar, there search priorities and discuss the policy implications of our is a need to better understand the drivers of coastal resource ’ research, especially the need for the integrated management use and the socio-ecological dynamics of the island s of ecosystems. mangroves. Here we document research on an emerging threat to mangroves in the Bay of Assassins in south-west Keywords Biodiversity, conservation–poverty linkages, de- Madagascar (Fig. ): the production of sokay, a sea-shell forestation, Madagascar, mangrove use, migration, poverty– based lime render produced in mangrove wood kilns and environment linkages used to improve the durability of houses. We consider data from a vegetation survey conducted in August ; semi-structured interviews with key informants (includ- ing six involved in lime production) undertaken in four vil- lages (Ampasimara, Lamboara, Tampolove and Vatoavo) in August ; and data from surveys and interviews carried IVAN R. SCALES (Corresponding author) Department of Geography, St out in (Epps, ) and (Blue Ventures, ). Catharine’s College, Cambridge, UK. E-mail [email protected]
DANIEL A. FRIESS Department of Geography, National University of Singapore, Singapore
LEAH GLASS and LALAO RAVAOARINOROTSIHOARANA Blue Forests Project, Blue The Bay of Assassins Ventures Conservation, Toliara, Madagascar Received August . Revision requested September . The Bay of Assassins (Helodrano Fanemotra in Malagasy) is Accepted November . a coastal inlet in south-west Madagascar, km north of
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PLATE 1 A house wall with wooden frame and lime render.
(Aina, ). Coastal in-migration and the commodification of marine resources in south-west Madagascar have in turn led to increasing pressure on fisheries (Aina, ; Barnes- Mauthe et al., ).
Mangrove use in the Bay of Assassins
Mangrove wood is harvested for two main purposes: the construction of houses and as a fuel in the construction of kilns to produce lime render. To estimate the effects of harvesting on mangroves we conducted measurements of canopy cover, structure and species composition in randomly selected -m radius circular plots within the bay. We counted, identified to species level, and measured the diameter at breast height of every tree (non-harvested and harvested). From our vegetation survey we found that every plot contained harvested trees, even those that were densely vegetated and relatively difficult to access. We FIG. 1 The Bay of Assassins, south-west Madagascar (mangrove found that the majority of tree harvesting involves the select cover data from Blue Ventures Conservation). felling of trees within mangrove stands, rather than clear cut- ting larger areas. Our mangrove plots had a mean canopy cover of . ± SE %, with a mean of . ± SE .%of the regional capital of Toliara. The inlet is fringed by c. , . ha of mangrove (Jones et al., ), dominated by Ceriops trees ( cm dbh) harvested. Although harvesting involves tagal and Rhizophora mucronata. There are villages mostly cutting trees at the trunk and thus killing the tree (as around the bay, with a total population of c. , Rhizophoraceae do not coppice or re-sprout), the forest is (Peabody & Jones, ). Small-scale fisheries generate generally cut in a way that leaves the majority of trees intact. over % of household income in these communities (Barnes-Mauthe et al., ). Lime production and use Coastal areas in Madagascar are increasingly experien- cing in-migration, as poor agricultural households move During our visits to four villages we observed that houses in to the coast seeking more secure livelihoods (Bruggemann the Bay of Assassins were made from a wide range of mate- et al., ). Data are scarce, but there is evidence that the rials, including reeds, wooden planks, corrugated iron Bay of Assassins is experiencing significant in-migration. sheets, and lime render over a wooden frame (Plate ). For example, in the villages of Lamboara and Ampasilava Our interviewees stated that lime render was the preferred , % of inhabitants were born in those settlements wall material because of its relative durability. However, (Epps, ). The region’s arid climate and the growth in lime production is a time consuming process, requiring marketing opportunities for marine produce have encour- kiln makers to cut a large volume of mangrove wood and aged people to turn from inland agriculture to coastal fishing collect sacks of sea shells. This means that the use of lime
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is limited to wealthier households who can afford to pay others to produce it. We observed kilns, at various stages of construction, in four villages. A lime kiln (Plate ) measures c. . min length, . m in width and . m in height, using mangrove poles of c. cm diameter. Layers of sea shells are sand- wiched between layers of wood. Favoured sea shells are those from gastropods such as Terebralia palustris and Murex ramosus (Epps, ). However, the kiln makers we interviewed reported that these species were increasingly difficult to obtain and that they were reliant on bivalves such as Donax faba, which are considered inferior because of their smaller and thinner shells. The preferred species of mangrove wood for kiln construc-
tion is Rhizophora mucronata, because of its high calorific PLATE 2 A lime kiln in the Bay of Assassins. value, although we noted that other species, such as Ceriops tagal, were also used. Kiln construction requires c. poles of mangrove wood, with a total volume of c. . m . A typical although the mangroves of the Bay of Assassins are heavily kiln produces – rice sacks of lime. An average sized house harvested, this mostly involves selective cutting, resulting in requires c. sacks to render. Each sack of lime sells for low-level disturbance. However, recent lime production has c. MGA , (USD .). A house thus costs c. MGA led to the clear cutting of mangrove forest in some instances. , (USD ) to render. To put this in perspective, the The area shown in Plate (a total of . ha) was cleared in average annual income in south-west Madagascar is , USD to fulfil a large commercial order from outside the vil- per person (INSTAT, ) and households spend lages. Although this is a small area, there are long-term im- . % of household income on food (WFP, ). plications for the site as canopy clearance often results in ’ As well as improving the durability of houses, lime ren- substantial surface subsidence (sensu Lang at et al., ; der is also considered a status symbol. Interviews with key Sasmito et al., ) limiting seedling regeneration, even informants suggested that lime use had increased over the after years. previous decade. This is supported by previous household surveys. In , % of households in Lamboara village Mangrove use and environmental policy in the Bay owned buildings with lime render invested in their con- of Assassins struction (Epps, ). By this figure had gone up to % (Blue Ventures, ). Furthermore, interviews revealed We have documented lime production and consumption that since lime producers have sold lime to individuals and how it relates to mangrove forests in the Bay of from outside the Bay of Assassins, providing evidence of a Assassins. Socio-economic surveys (Epps, ; Blue lime commodity network that extends beyond the Bay. Ventures, ) and interviews with key informants suggest Key informants suggest that growing wealth from sea cu- that the use of lime render has increased as a result of a rise cumber (Holothuria spp.) and seaweed Kappaphycus alvar- in the income of some households. This relates in part to ezii aquaculture, along with octopus Octopus cyanea fishing, new sources of income that have been created as villages has contributed to growing demand for lime as some house- in the Bay of Assassins have become connected to global holds can afford to pay others in the village to produce it. All commodity chains for octopus, seaweed and sea cucumber. three of these marine products have experienced rapid com- This research has highlighted the complex relationship modification, with fishers now supplying global markets. between poverty, income growth and resource use. Our For example, commercial trade in octopus only started in findings suggest that it is not simply poverty that drives pat- in the region, with export trade starting in and terns of mangrove use and change in the Bay of Assassins. middlemen visiting villages to collect fresh octopus for ex- Rising incomes have created new pressures in the form of port (Aina, ). demand for lime render, which is met by other households who produce it commercially. While research on charcoal production in communities inland has found that it is car- Lime production as a threat to mangrove quality ried out primarily by poor households who have abandoned and quantity farming (Gardner et al., ), the socio-economic charac- teristics of lime producers is not yet known. Mangrove wood Changes in lime production and use have important impli- use needs to be quantified through a comprehensive house- cations for mangroves. Our vegetation surveys show that hold survey and particular attention needs to be paid to
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aquaculture), terrestrial forests, and mangroves at the same time and examines links between them.
Acknowledgements
This research was funded through an Environment and Sustainability Grant from the Royal Geographical Society (with IBG). We thank Michael Strongoff, Jose Njara Ranaivoson and Helen Scales for field assistance, Al Harris and Blue Ventures for their logistical support, Philip Stickler (Department of Geography, University of Cambridge) for cartographic assistance, and two anonym- ous reviewers for their helpful comments and suggestions.
PLATE 3 Clear cutting of Rhizophora mucronata and Ceriops tagal in response to demand for lime in . Author contributions
IRS and DAF designed the study, carried out the vegetation differences between households in lime production and survey, analysed the data, and drafted the article. All authors consumption, for example according to wealth and migra- contributed field observations and interview data, and read tion status. If migration into coastal villages continues, in- and revised the article. comes rise, and demand for building timber and lime render grows, how can mangrove harvesting patterns and rates be managed in such a way as to allow mangrove References regeneration?
We have also found that lime commodity chains extend AINA, T.A.N. () Management of Octopus Fisheries off South West outside the villages of the Bay of Assassins. External demand Madagascar. United Nations University Fisheries Training has led to a different harvesting pattern, with mangrove Programme, Iceland. clearance rather than selective cutting. The extent of lime BANDARANAYAKE, W.M. () Traditional and medicinal uses of – commodity chains and the size of the market for lime is un- mangroves. Mangroves and Salt Marshes, , . BARBIER, E.B., HACKER, S.D., KENNEDY, C., KOCH, E.W., STIER, A.C. known. There is also a need for research on the socio- &SILLIMAN, B.R. () The value of estuarine and coastal ecological dynamics of sea-shell collection, particularly the ecosystem services. Ecological Monographs, , –. quantity and species of molluscs targeted, how shell collec- BARNES-MAUTHE, M., OLESON, K.L.L. & ZAFINDRASILIVONONA,B. tors are responding to scarcity, and the ecological impacts of () The total economic value of small-scale fisheries with a shell collection. characterization of post-landing trends: an application in Madagascar with global relevance. Fisheries Research, , –. Our findings suggest that mangroves must be managed BLUE VENTURES () Mangrove Use in the Bay of Assassins. Blue as part of broader landscape-based approaches. There is Ventures Conservation, London, UK. now abundant research showing that mangroves are inter- BRUGGEMANN, J.H., RODIER, M., GUILLAUME, M.M.M., linked with other ecosystems in important ways; for ex- ANDRÉFOUËT, S., ARFI, R., CINNER, J.E. et al. () Wicked social– ample, mangroves act as hatcheries for coral reef and ecological problems forcing unprecedented change on the latitudinal margins of coral reefs: the case of southwest Madagascar. pelagic fish species (Nagelkerken et al., ). Our docu- Ecology and Society, , . mentation of lime production shows that links between eco- COSTANZA, R., DE GROOT, R., SUTTON, P., SANDER VAN DER PLOEG, systems are also socio-economic. Changes in one system S., ANDERSON, S.J., KUBISZEWSKI, I. et al. () Changes in the (e.g. growing income from aquaculture) can affect another global value of ecosystem services. Global Environmental Change, (e.g. loss of mangrove cover through increased demand for , –. lime). In turn, the loss of mangroves has implications for CRIPPS,G.&HARRIS,A.( ) Community Creation and Management of the Velondriake Marine Protected Area. Blue fisheries because of the role of mangroves in the life cycles Ventures Conservation, London, UK. of fish and other marine fauna important to the livelihoods DUKE, N.C., MEYNECKE, J.O., DITTMANN, S., ELLISON, A.M., ANGER, of rural households in fishing communities (Duke et al., K., BERGER, U. et al. () A world without mangroves? Science, ; Nagelkerken et al., ). In the Bay of Assassins live- , –. lihoods draw on coral reefs, sea grasses, mangroves and ter- EPPS,M.( ) A Socioeconomic Baseline Assessment: Implementing the Socioeconomic Monitoring Guidelines in Southwest Madagascar. restrial dry forests (Epps, ; Cripps & Harris, ; Blue Ventures Conservation, London, UK. Peabody & Jones, ). It is therefore crucial that environ- GARDNER, C.J., GABRIEL, F.U.L., ST JOHN, F.A.V. & DAVIES, Z.G. mental policy considers marine resources (fisheries and () Changing livelihoods and protected area management: a case
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