The economic importance of freshwater crayfish harvesting in Madagascar and the potential of community-based conservation to improve management

Abstract

Madagascar's endemic freshwater crayfish (Parastacidae: Astacoides) are harvested by local people for both subsistence use and small-scale trade. There has been concern that populations, and even species, are threatened by overexploitation but little is known about the harvest or its economic importance. We studied crayfish exploitation in eastern Madagascar over 3 years. The existence of local taboos (fady) preventing commercial crayfish harvesting, as well as access to markets and forest, influenced involvement in the harvest. All four crayfish species found in the region were harvested, but A. granulimanus provided the majority of the catch. In one harvesting village more than 50% of the 47 households were directly involved in the harvest, which contributed USD 2,382 to the village economy in 2003/2004, an important sum in the context of local incomes. Subsistence use was widespread, particularly by children to whom it may provide an important protein source.Community-based conservation (through transfer of harvesting rights and responsibilities for forest management to local communities) is central to a new conservation paradigm in Madagascar. This recognizes communities' long term interest in their natural resources and offers an ideal opportunity for those concerned with the sustainability of the harvest to implement management tools (such as avoiding reproductive females, size limits and no-take zones). We discuss each tool with respect to biological implications and practical constraints. We note that community-based approaches may not be sufficient to conserve rarer species, which make up a small proportion of the value of the harvest.

Three flying fox (Pteropodidae: Pteropus rufus) roosts, three conservation challenges in southeastern Madagascar

“…In other circumstances, taboo might not determine which species are eaten but it may impact the way in which the animal is exploited (e.g. Jones et al 2006). However, in many areas fady is being eroded and as this occurs the animals that were once traditionally protected are exploited (e.g.…”

“…In many parts of Madagascar local taboo (or fady) governs resource use and can benefit species conservation because certain taxa are forbidden to be hunted or consumed (e.g. Jones et al 2006). In our study there was some evidence for this because the Antandroy people rarely ate P. rufus because it was taboo.…”

Towards a sustainable human use of freshwater crayfish (Crustacea, Decapoda, Astacidea)

“…However, less than 6% of the harvest is consumed by the villagers, although crayfish contribution to providing proteins to the young is relevant (Jones et al, 2006). Most harvested crayfish are sold to passers-by or to stallholders.…”

Effect of mesh size on baited trap catch composition for noble crayfish (Astacus Astacus)

“…The species is also included in international (IUCN, 1996) and national (Kålås et al, 2010) red lists. It has been argued that the possibility for exploitation and economical as well as recreational benefits among local inhabitants may increase the interest for conservation (Taugbøl, 2004;Jones et al, 2006;Zimmerman, 2012). This implies that the management of noble crayfish needs to consider carefully the balance between conservation and utilisation.…”