Erickson [Erickson CL (2000) Nature 408 (6809):190–193] interpreted features in seasonal floodplains in Bolivia’s Beni savannas as vestiges of pre-European earthen fish weirs, postulating that they supported a productive, sustainable fishery that warranted cooperation in the construction and maintenance of perennial structures. His inferences were bold, because no close ethnographic analogues were known. A similar present-day Zambian fishery, documented here, appears strikingly convergent. The Zambian fishery supports Erickson’s key inferences about the pre-European fishery: It allows sustained high harvest levels; weir construction and operation require cooperation; and weirs are inherited across generations. However, our comparison suggests that the pre-European system may not have entailed intensive management, as Erickson postulated. The Zambian fishery’s sustainability is based on exploiting an assemblage dominated by species with life histories combining high fecundity, multiple reproductive cycles, and seasonal use of floodplains. As water rises, adults migrate from permanent watercourses into floodplains, through gaps in weirs, to feed and spawn. Juveniles grow and then migrate back to dry-season refuges as water falls. At that moment fishermen set traps in the gaps, harvesting large numbers of fish, mostly juveniles. In nature, most juveniles die during the first dry season, so that their harvest just before migration has limited impact on future populations, facilitating sustainability and the adoption of a fishery based on inherited perennial structures. South American floodplain fishes with similar life histories were the likely targets of the pre-European fishery. Convergence in floodplain fish strategies in these two regions in turn drove convergence in cultural niche construction.
Present-day African analogue of a pre-European Amazonian floodplain fishery shows convergence in cultural niche construction
Auteurs : McKey, Doyle B. and Durécu, Mélisse and Pouilly, Marc and Béarez, Philippe and Ovando, Alex and Kalebe, Mashuta and Huchzermeyer, Carl F. - Proceedings of the National Academy of Sciences (PNAS), 15 décembre 2016. doi = 10.1073/pnas.1613169114
Contact : Marc Pouilly, chercheur IRD, équipe 6 de l'UMR BOREA
Légende figure :
Seasonal floodplain landscapes bearing large numbers of earthen fish weirs (white arrows). (A) The present-day fishery in the Bangweulu basin, Zambia, described in this study. Multispectral satellite image by the Pléiades sensor, 12°00′S, 29°42′E, September 17, 2013 (Copyright 2013, CNES, Distribution Airbus DS, all rights reserved). (B) The archaeological fishery in Bolivian Amazonia described by Erickson (1). Image from Google Earth V7.1.5.1557; 13°51′S, 63°19′W. (C) Fishways (white arrow) in weirs in the Bangweulu basin, Zambia. Multispectral satellite image by the Pléiades sensor, 12°00′S, 29°42′E, September 17, 2013 (Copyright 2013, CNES, Distribution Airbus DS, all rights reserved). (D) Vestiges of V-shaped structures (white arrow) in the archaeological fishery in Bolivia. Image (13°45′30′′, 63°18′’52′′W) from “World Imagery” layer of ArcGis. Source: ESRI, Digital Globe, satellite WorldView1, June 2008.