Interrelations between mangrove ecosystem, local economy and social sustainability in Caeté Estuary, North Brazil
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M. Glaser


Various types of subsistence and commercial extraction of mangrove products are identified on the North Brazilian coast. Of 2500 households in 21 rural communities (about 13.000 people) near the Caeté estuary, 83% derive subsistence income, and 68% cash income through use of mangrove resources.  The mangrove crab (Ucides cordatus) is collected and sold by 42% of households, and constitutes a main income source for 38%. Including processing and trading occupations, over half of the investigated population depends on the mangrove crab for financial income. Mangrove fishery occupies the lower rural income groups in the fisheries sector. About 30% of households engage in commercial fishing in or near the mangrove. Illegal commercial and subsistence use of mangrove wood and bark maintains a considerable number of rural households. (Deforestation). In the context of widespread rural poverty in coastal North Brazil, it is important for mangrove management to take into account subsistence production, which has a central socio-economic function for the rural poor who live close to the mangroves. Socio-economic priorities in mangrove villages were, in order of importance, educational quality, occupational options, medical care, the low level of mangrove product prices, access to electricity and local leadership quality.

Main Results and Conclusions:
  • The rural communities of the Caeté estuary rely heavily on mangrove ecosystem goods and services for subsistence purposes:
    • “Their economic, social and cultural life is closely interwoven with the surrounding flora and fauna, its lunar and tidal and seasonal cycles and their associated fish, crab and other floral and faunal reproduction seasons”(266).
    • “Grasso (2000) assigns market prices to mangrove subsistence production and finds high subsistence values for products such as the ship bore worm (Teredo sp.), at US$ 122.00/month; the river crab (Callinectes sp.) at US$ 41,50/month; and mussels (Fam. Mytilidae) at US$ 35,00/month”(267).
    • “Although subsistence production does not generate cash income, it fulfils an important poverty alleviation function in the rural household economy”(267).
    • “Mostly women and children collect those mangrove products”- products from bullet point (b)-“, which are used by few households, and purely for subsistence purposes (right side of Figure 1). These products…have a clear emergency food provision function for the poorest rural families”(267).
  • Mangrove products used for commercial purposes are an important part of these rural communities’ economy:
    • “The commercially most important species, the mangrove crab (Ucides cordatus) is collected and sold by 42% of research area households, and represents the main income source for 38%”(268).
    • “About 30% of households in the study area engage in commercial fishing in or near the mangrove”(268).
    • Mangrove wood products were also very important to many of the households, despite the illegality of mangrove wood extraction. In addition to illegal wood extraction by households, deforested areas indicate “intrusion of leather tanning manufacturers into the mangroves for collection of tree bark and the use of mangrove wood for brick kilns and bakery ovens”(268).  (Deforestation).
  • The dependence on mangroves for both commercials and subsistence use is extensive: “More than eight in ten households depend on the mangrove, in the sense that they extract subsistence or commercial products from the ecosystem or are in mangrove dependent occupations. 68% of households earn cash income by selling mangrove ecosystem products”(269).
  • In conclusion:
    • “While subsistence dependence on mangroves is important for social sustainability, capture volumes of U. cordatus in the research area are clearly market-driven and mangrove-related commercial production is generating the greatest pressure on resources”(270).
    • “It is argued here, that in the context of widespread rural poverty in North Brazil it is clearly essential for natural resource management to take into account pure subsistence production, i.e. that part of human mangrove use which never reaches the market but which assumes an economic and social life support function for the majority of the increasing numbers of people who live close to the mangroves”(271).
Works Cited:

Glaser, M. and Grasso, M. 2000. Economic Valuation of a Mangrove Ecosystem: Practical Implications for Management. INTERCOAST, Coastal Resources Center, University of Rhode Island, No 35: pp. 27–29.