@article {6107, title = {Seasonal oxygen isotope variations in freshwater bivalve shells as recorders of Amazonian rivers hydrogeochemistry}, journal = {Isotopes in Environmental and Health Studies}, year = {2019}, pages = {1-15}, type = {Journal Article}, abstract = {

Freshwater bivalve shell oxygen isotope values (δ18OS) may act as a recorder of river δ18O variations that can then be interpreted in terms of hydrology (e.g. precipitation{\textendash}evaporation balance, precipitation and river discharge patterns). We investigated the potential of this proxy measured across the hinge of South American unionid shells: Anodontites elongatus collected in Peru and A. trapesialis in Brazil. The isotopic signatures were reproducible between individuals of the same species. A. trapesialis clearly showed a strong δ18OS cyclicity in accordance with its growth patterns while A. elongatus presented less clear δ18OS with lower amplitude. We confirm that the deposition of successive growth lines and increments is annual, with growth line corresponding to the wet season. Also, we suggest that low amplitude of δ18OS in the A. elongatus shells indicates a habitat close to the river while large amplitude of δ18OS cycles observed in A. trapesialis shells would reflect a floodplain lake habitat, seasonally disconnected from the river and thus subjected to higher seasonal fluctuations in water δ18O. Considering these promising first results, future studies could be directed towards the use of fossil shells to reconstruct the past and present hydrological and geochemical conditions of the Amazon.

}, keywords = {Amazon basin, freshwater bivalve shells, hydroclimate, isotope ecology, isotope hydrology, oxygen isotopes}, issn = {1025-6016 1477-2639}, doi = {10.1080/10256016.2019.1666120}, url = {https://hal.archives-ouvertes.fr/hal-02314885v1}, author = {Gaillard, Blandine and Claire E. Lazareth and Lestrelin, Hugo and Dufour, Elise and Santos, Roberto V. and Carlos E.C. Freitas and Marc Pouilly} } @article {7036, title = {Shedding light on the migratory patterns of the Amazonian goliath catfish, Brachyplatystoma platynemum , using otolith 87 Sr/ 86 Sr analyses}, journal = {Aquatic Conservation: Marine and Freshwater Ecosystems}, volume = {29}, year = {2019}, month = {Aug-03-2020}, pages = {397 - 408}, issn = {1052-7613}, doi = {10.1002/aqc.v29.310.1002/aqc.3046}, url = {https://onlinelibrary.wiley.com/toc/10990755/29/3}, author = {Hauser, Marilia and Doria, Carolina R.C. and Santos, Roberto V. and Garc{\'\i}a-Vasquez, Aurea and Marc Pouilly and Pecheyran, Christophe and Ponzevera, Emmanuel and Torrente-Vilara, Gislene and B{\'e}rail, Sylvain and Panfili, Jacques and Darnaude, Audrey and Renno, Jean-Fran{\c c}ois and Garc{\'\i}a-D{\'a}vila, Carmen and Jesus Nu{\~n}ez-Rodriguez and Ferraton, Franck and Vargas, Gladys and Duponchelle, Fabrice} } @article {4280, title = {Trans-Amazonian natal homing in giant catfish}, journal = {Journal of Applied Ecology}, volume = {53}, year = {2016}, pages = {1511-1520}, abstract = {

1.Knowledge of fish migration is a prerequisite to sustainable fisheries management and preservation, especially in large international river basins. In particular, understanding whether a migratory lifestyle is compulsory or facultative, and whether adults home to their natal geographic area is paramount to fully appraise disruptions of longitudinal connectivity resulting from damming.2.In the Amazon, the large migratory catfishes of the Brachyplatystoma genus are apex predators of considerable interest for fisheries. They are believed to use the entire length of the basin to perform their life cycle, with hypothesized homing behaviours. Here we tested these hypotheses, using the emblematic B. rousseauxii as a model species.3.We sampled adults close to major breeding areas in the Amazon basin (upper Madeira and upper Amazonas) and assessed their lifetime movements by measuring variations in 87Sr/86Sr along transverse sections of their otoliths (ear stones) using laser ablation multicollector mass spectrometry (LA-MC-ICPMS).4.We demonstrate that larvae migrate downstream from the Andean piedmont to the lower Amazon, where they grow over a protracted period before migrating upstream as adults. Contrary to prevailing inferences, not all fish spend their nursery stages in the Amazon estuary. By contrast, the passage in the lower or central Amazon seems an obligate part of the life cycle. We further evidence that most adults home to their natal geographic area within the Madeira sub-basin. Such long-distance natal homing is exceptional in purely freshwater fishes.5.Synthesis and applications. By using otolith microchemistry, we were able to demonstrate a seemingly compulsory basin-wide migratory life cycle of large Amazonian catfishes. This makes them the organisms performing the longest migrations (\>8000 km) in fresh waters. This exceptional life history is already jeopardized by two dams recently built in the Madeira River, which block a major migration route and access to a substantial part of their spawning grounds. Major impacts can be anticipated from the current and forthcoming hydroelectric development in the Amazon basin, not only on the populations and fisheries of this apex predator, but also on Amazonian food webs through trophic cascades.This article is protected by copyright. All rights reserved.

}, keywords = {87Sr/86Sr ratios, Amazon, anthropogenic activities, Brachyplatystoma spp, freshwater fish, giant catfish, hydroelectric dams, Migration, otoliths}, issn = {1365-2664}, doi = {10.1111/1365-2664.12665}, url = {http://dx.doi.org/10.1111/1365-2664.12665}, author = {Fabrice Duponchelle and Marc Pouilly and Pecheyran, Christophe and Hauser, Marilia and Renno, Jean-Francois and Panfili, Jacques and Darnaude, Audrey M. and Garc{\'\i}a-Vasquez, Aurea and Carvajal-Vallejos, Fernando and Carmen Garc{\'\i}a-D{\'a}vila and Doria, Carolina and B{\'e}rail, Sylvain and Donard, Ariane and Sondag, Francis and Santos, Roberto V. and Jesus Nu{\~n}ez-Rodriguez and Point, David and Labonne, Maylis and Baras, Etienne} }