Intensive fishing has not forced dietary change in the South American fur sealArctophoca(=Arctocephalus)australisoff Río de la Plata and adjoining areas

Napoleon Bonaparte’s 1807 invasion of Spain and Portugal set in motion a transatlantic imperial crisis that, within two decades, resulted in Spain’s losing nearly all of its American possessions. Typically, the founding of most Spanish South American nations is attributed to the heroic leadership of the great liberators: Simón Bolívar and José de San Martín. While San Martín is most famous for organizing the Army of the Andes that carried out the liberation of Chile, parts of Peru, and eventually, in 1822, reunited with Bolívar in Ecuador, his time in western Río de la Plata building his army is less understood. From 1814 until 1817, General San Martín took up residence in the western Río de la Plata (Argentina) city of Mendoza to build an army capable of defeating Spanish rule in Chile and Peru. To receive permission to cross the Andes westward into Chile, San Martín needed more than soldiers well trained in European military style and horses: he needed to negotiate with the local Pehuenche people—part of the broader Mapuche peoples of southern Chile and western Río de la Plata—who had successfully resisted Spanish conquest for centuries. Before San Martín could cross the Andes to invade Chile, he participated in two interethnic diplomatic rituals known as parlamentos in Spanish and koyang in Mapudungun, with the Pehuenche. Nearly forty recorded Spanish–Mapuche parlamentos had taken place in Chile and near Mendoza since 1593. In the two 1816 parlamentos, interpreters translated the negotiations between Pehuenche representatives and San Martín over the exchange of horses, the giving of gifts, the recognition of Pehuenche dominion, and permission for the Army of the Andes to cross the mountains west to Chile. While San Martín chose to spread news of this agreement to confuse the Spanish forces in Chile as to the location of their crossing, opting not to cross Pehuenche lands, these parlamentos nevertheless speak to the power and importance of Pehuenche political traditions during the Age of Revolution.

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Sexual foraging segregation in South American sea lions increases during the pre-breeding period in the Río de la Plata plume

Marine Ecology Progress Series ◽

10.3354/meps11236 ◽

2015 ◽

Vol 525 ◽

pp. 261-272 ◽

Cited By ~ 13

Author(s):

M Drago ◽

V Franco-Trecu ◽

L Zenteno ◽

D Szteren ◽

EA Crespo ◽

...

Keyword(s):

Breeding Period ◽

South American ◽

Rio De La Plata ◽

Río De La Plata ◽

La Plata ◽

Sea Lions

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Variability in terrigenous sediment supply offshore of the Río de la Plata (Uruguay) recording the continental climatic history over the past 1200 years

Climate of the Past ◽

10.5194/cp-12-623-2016 ◽

2016 ◽

Vol 12 (3) ◽

pp. 623-634 ◽

Cited By ~ 23

Author(s):

Laura Perez ◽

Felipe García-Rodríguez ◽

Till J. J. Hanebuth

Keyword(s):

Continental Shelf ◽

Rio De La Plata ◽

The South ◽

Río De La Plata ◽

La Plata ◽

The Past ◽

Element Ratios ◽

Terrigenous Input ◽

Freshwater Plume ◽

Freshwater Diatom

Abstract. The continental shelf adjacent to the Río de la Plata (RdlP) exhibits extremely complex hydrographic and ecological characteristics which are of great socioeconomic importance. Since the long-term environmental variations related to the atmospheric (wind fields), hydrologic (freshwater plume), and oceanographic (currents and fronts) regimes are little known, the aim of this study is to reconstruct the changes in the terrigenous input into the inner continental shelf during the late Holocene period (associated with the RdlP sediment discharge) and to unravel the climatic forcing mechanisms behind them. To achieve this, we retrieved a 10 m long sediment core from the RdlP mud depocenter at 57 m water depth (GeoB 13813-4). The radiocarbon age control indicated an extremely high sedimentation rate of 0.8 cm per year, encompassing the past 1200 years (AD 750–2000). We used element ratios (Ti  / Ca, Fe / Ca, Ti / Al, Fe / K) as regional proxies for the fluvial input signal and the variations in relative abundance of salinity-indicative diatom groups (freshwater versus marine-brackish) to assess the variability in terrigenous freshwater and sediment discharges. Ti / Ca, Fe / Ca, Ti /  Al, Fe /  K and the freshwater diatom group showed the lowest values between AD 850 and 1300, while the highest values occurred between AD 1300 and 1850. The variations in the sedimentary record can be attributed to the Medieval Climatic Anomaly (MCA) and the Little Ice Age (LIA), both of which had a significant impact on rainfall and wind patterns over the region. During the MCA, a weakening of the South American summer monsoon system (SAMS) and the South Atlantic Convergence Zone (SACZ), could explain the lowest element ratios (indicative of a lower terrigenous input) and a marine-dominated diatom record, both indicative of a reduced RdlP freshwater plume. In contrast, during the LIA, a strengthening of SAMS and SACZ may have led to an expansion of the RdlP river plume to the far north, as indicated by higher element ratios and a marked freshwater diatom signal. Furthermore, a possible multidecadal oscillation probably associated with Atlantic Multidecadal Oscillation (AMO) since AD 1300 reflects the variability in both the SAMS and SACZ systems.

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