First Characterization of PAH-degrading bacteria from Río de la Plata and high-resolution melting: an encouraging step toward bioremediation

ABSTRACT. This paper addresses the characterization of the geomorphology and palaeo-evolution of the La Plata River on the south Brazilian continental shelf,through bathymetric data and sedimentary and palynological analysis from sediment core samples. The analysis allowed us to characterize a transgressive depositionalsequence in the La Plata River palaeo-channel. The palynological sequences revealed continental fresh water environments, that involved into lagoonal and mixohalineenvironments and then into shallow marine environments towards the top, thus characterizing a fluvial-estuarine environment. These new data offer sufficient informationto establish the palaeo-geographic evolution of the La Plata River palaeo-channel and its local influence on the sedimentation of the Rio Grande do Sul Statecontinental shelf.Keywords: palaeo-valley, continental shelf, marine transgression, La Plata River. RESUMO. O presente trabalho trata da evolução e caracterização geomorfológica do paleocanal do rio de La Plata sobre a plataforma continental sul-brasileira.A partir da análise de dados de levantamento batimétrico e da obtenção de testemunhos no paleocanal, coletados para fins de estudo morfológico, sedimentológico epalinológico, foi possível identificar sequências deposicionais transgressivas. Os registros palinológicos evidenciaram ambientes com influência continental de água doce, migrando para lagunar, mixohalino e marinho raso, em direção ao topo dos testemunhos, caracterizando um ambiente fluvio-estuarino. Os resultados obtidoscontribuem para o estabelecimento da evolução paleogeográfica e da influência do paleocanal do rio de La Plata na sedimentação, de parte, da plataforma continentaldo Rio Grande do Sul.Palavras-chave: paleovale, plataforma continental, transgressão marinha, rio de La Plata.

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Detecting and Quantifying a Massive Invasion of Floating Aquatic Plants in the Río de la Plata Turbid Waters Using High Spatial Resolution Ocean Color Imagery

Remote Sensing ◽

10.3390/rs10071140 ◽

2018 ◽

Vol 10 (7) ◽

pp. 1140 ◽

Cited By ~ 13

Author(s):

Ana Dogliotti ◽

Juan Gossn ◽

Quinten Vanhellemont ◽

Kevin Ruddick

Keyword(s):

High Resolution ◽

Aquatic Plants ◽

Color Space ◽

Landsat 8 ◽

Rio De La Plata ◽

Río De La Plata ◽

La Plata ◽

Turbid Waters ◽

High Resolution Imagery ◽

Floating Vegetation

The massive development of floating plants in floodplain lakes and wetlands in the upper Middle Paraná river in the La Plata basin is environmentally and socioeconomically important. Every year aquatic plant detachments drift downstream arriving in small amounts to the Río de la Plata, but huge temporary invasions have been observed every 10 or 15 years associated to massive floods. From late December 2015, heavy rains driven by a strong El Niño increased river levels, provoking a large temporary invasion of aquatic plants from January to May 2016. This event caused significant disruption of human activities via clogging of drinking water intakes in the estuary, blocking of ports and marinas and introducing dangerous animals from faraway wetlands into the city. In this study, we developed a scheme to map floating vegetation in turbid waters using high-resolution imagery, like Sentinel-2/SMI (MultiSpectral Imager), Landsat-8/OLI (Operational Land Imager), and Aqua/MODIS (MODerate resolution Imager Spectroradiometer)-250 m. A combination of the Floating Algal Index (that make use of the strong signal in the NIR part of the spectrum), plus conditions set on the RED band (to avoid misclassifying highly turbid waters) and on the CIE La*b* color space coordinates (to confirm the visually “green” pixels as floating vegetation) were used. A time-series of multisensor high resolution imagery was analyzed to study the temporal variability, covered area and distribution of the unusual floating macroalgae invasion that started in January 2016 in the Río de la Plata estuary.

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