Philippe Béarez

Quebrada de los burros: Los primeros pescadores del litoral pacífico en el extremo sur peruano

Resumen es: Las excavaciones en la Quebrada de los Burros, en el litoral de Tacna (Peru), han descubierto un campamento de pescadores y recolectores de moluscos (QlB...

Present-day African analogue of a pre-European Amazonian floodplain fishery shows convergence in cultural niche construction

Significance Erickson convincingly inferred a pre-European floodplain fishery unlike any present-day system he knew, illustrating the principle that archaeological inference should not be constrained by the range of cultural variation observed today. Our comparison of these inferences with observations from a present-day fishery in a similar environment suggests strong convergence in both the ecology of fish communities and the cultural means people have devised to exploit them, providing support for a predictive model of cultural niche construction. This conceptual framework emphasizes the synergistic action of human agency and environmental constraint in shaping patterns in the human use and management of ecosystems. 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.

The Las Salinas palaeo-lagoon in the Sechura Desert (Peru): Evolution during the last two millennia

The Sechura Desert provides a unique example of a vast palaeo-lagoon system on the Peruvian coast that was active during the first millennium AD. Reconstruction of coastal evolution is made possible by the good resolution of the sedimentary records of the Las Salinas Noroeste coastal plain. Evidence from morphostratigraphy and sedimentary facies indicates marked environmental diversity between the 3rd and the 8th centuries AD and a wide variability of sedimentary dynamics: lagoon foreshores received alternately fine distal marine sediments and coarser continental sediments in pro-deltaic sheets. Evaporation phases periodically occurred in these foreshores causing the formation of salt crusts. After a last high water level in the 8th century AD, the lagoon ultimately dried out and remains dry today. The malacofauna and sedimentary facies indicate that marine marshes bordered by vegetation, perhaps mangrove, developed in the higher parts of these lagoons. This palaeogeography is explained by the progressive build-up of a sand bar which started at least in the middle Holocene. From the 3rd to 8th centuries AD, the lagoon had limited connection to the sea in its northern end and hosted a warm-water and productive ecosystem that was exploited by pre-Hispanic populations. Wetter conditions in the Andes and occasional El Niño rainfalls maintained the lagoon during this period. The freshwater input likely stopped in the 8th century AD, which led to the closing of the shore bar under the influence of the longshore drift rapidly followed by the drying up of the lagoon, and the abandonment of the archaeological site.

The unique functioning of a pre-Columbian Amazonian floodplain fishery

Archaeology provides few examples of large-scale fisheries at the frontier between catching and farming of fish. We analysed the spatial organization of earthen embankments to infer the functioning of a landscape-level pre-Columbian Amazonian fishery that was based on capture of out-migrating fish after reproduction in seasonal floodplains. Long earthen weirs cross floodplains. We showed that weirs bear successive V-shaped features (termed ‘Vs’ for the sake of brevity) pointing downstream for outflowing water and that ponds are associated with Vs, the V often forming the pond’s downstream wall. How Vs channelled fish into ponds cannot be explained simply by hydraulics, because Vs surprisingly lack fishways, where, in other weirs, traps capture fish borne by current flowing through these gaps. We suggest that when water was still high enough to flow over the weir, out-migrating bottom-hugging fish followed current downstream into Vs. Finding deeper, slower-moving water, they remained. Receding water further concentrated fish in ponds. The pond served as the trap, and this function shaped pond design. Weir-fishing and pond-fishing are both practiced in African floodplains today. In combining the two, this pre-Columbian system appears unique in the world.

External morphology, postcranial and appendicular osteology of three southwestern Atlantic flatfishes ( Paralichthys , Paralichthyidae), and comparisons with other congeneric species

Comparisons of the external morphology and analysis of osteological features of the postcranial and appendicular skeletons of three southwestern Atlantic flatfish species of the genus Paralichthys (P. isosceles, P. orbignyanus and P. patagonicus) were carried out. Bones are described, and detailed morphological, morphometric and meristic characteristics of these flounders are given in order to provide information about the external and internal morphology of three species of Paralichthys occurring in the south-west Atlantic waters that add new information and will help regarding within the framework of a phylogenetic study of the group. Interspecific differences were found in the number of vertebrae and intermuscular bones, as well as in the morphology and morphometry of vertebrae, caudal skeletons, pectoral and pelvic girdle bones. Relationships between bones are discussed and bone characteristics compared with those found in other species of Paralichthys and in other pleuronectiform species. The position of Paralichthys isosceles within Paralichthys is discussed, along with other congeners such as P. triocellatus and P. oblongus.(AU)