scholarly journals 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

2018 ◽  
Vol 10 (7) ◽  
pp. 1140 ◽  
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.

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

2018 ◽  
Vol 40 (10) ◽  
pp. 1250-1261 ◽  
Author(s):  
Silvina A. Izzo ◽  
Silvina Quintana ◽  
Mariela Espinosa ◽  
Paola A. Babay ◽  
Silvia R. Peressutti
Keyword(s):  
High Resolution ◽  
High Resolution Melting ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Degrading Bacteria

scholarly journals Evaluating the performance of the OC5 algorithm of IFREMER for the highly turbid waters of Río de la Plata

2016 ◽  
Vol 64 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Martina Daniela Camiolo ◽  
Ezequiel Cozzolino ◽  
Claudia Gloria Simionato ◽  
María Constanza Hozbor ◽  
Carlos Ángel Lasta
Keyword(s):  
Poor Performance ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Turbid Waters ◽  
Global Vision ◽  
Point Correlation ◽  
Point To Point

Abstract Remote sensing provides a global vision of the oceans; validation is, however, an essential previous step. IFREMER developed the empirical algorithm OC5 for highly turbid (or type 2) waters and it performed well for the northwestern European shelf. The aim of this study was to evaluate the performance of this algorithm for the Río de la Plata estuary, utilizing in situ observations of chlorophyll-a and suspended matter. Our results show a low point-to-point correlation between in situ and remote observations for both variables. In addition, the root mean square log error (RMSE) exceeded 35% for both variables, indicating a poor performance of the OC5 algorithm. This might be related to the empirical nature of the algorithm, to the amount and distribution of the data used for the analysis, to the species that compose the phytoplankton of the region, to the presence of other optically active substances in the water, and to errors in the atmospheric corrections and/or to the spatial variability of the analyzed variables. In conclusion, our results confirm the need to develop regional algorithms which take into account the particular physical and biological characteristics of the area under study.

Atmospheric Correction of Satellite Optical Imagery over the Río de la Plata Highly Turbid Waters Using a SWIR-Based Principal Component Decomposition Technique

2021 ◽  
Vol 13 (6) ◽  
pp. 1050
Author(s):  
Juan Ignacio Gossn ◽  
Robert Frouin ◽  
Ana Inés Dogliotti
Keyword(s):  
Principal Components ◽  
Near Infrared ◽  
Atmospheric Correction ◽  
Low Noise ◽  
Optical Data ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Turbid Waters ◽  
The Impact

Estimating water reflectance accurately from satellite optical data requires implementing an accurate atmospheric correction (AC) scheme, a particularly challenging task over optically complex water bodies, where the signal that comes from the water prevents using the near-infrared (NIR) bands to separate the perturbing atmospheric signal. In the present work, we propose a new AC scheme specially designed for the Río de la Plata—a funnel-shaped estuary in the Argentine–Uruguayan border—highly scattering turbid waters. This new AC scheme uses far shortwave infrared (SWIR) bands but unlike previous algorithms relates the atmospheric signal in the SWIR to the signal in the near-infrared (NIR) and visible (VIS) bands based on the decomposition into principal components of the atmospheric signal. We describe the theoretical basis of the algorithm, analyze the spectral features of the simulated principal components, theoretically address the impact of noise on the results, and perform match-ups exercises using in situ measurements and Moderate Resolution Imaging Spectrometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) imagery over the region. Plausible water reflectance retrievals were obtained in the NIR and VIS bands from both simulations and match-ups using field data—with better performance (i.e., lowest errors and offsets, and slopes closest to 1) compared to existing AC schemes implemented in the NASA Data Analysis Software (SeaDAS). Moreover, retrievals over images in the VIS and NIR bands showed low noise, and the correlation was low between aerosol and water reflectance spatial fields.

An interesting new record of the almost unknown brachypterous phaneropterine katydid Xenicola dohrni (Orthoptera: Tettigoniidae) from Argentina, and its high-ultrasound male-female communication

Zootaxa ◽  
2021 ◽  
Vol 4948 (2) ◽  
pp. 287-294
Author(s):  
HOLGER BRAUN
Keyword(s):  
Acoustic Communication ◽  
Carrier Frequency ◽  
New Record ◽  
Rio De La Plata ◽  
Southern Brazil ◽  
Frequency Range ◽  
Río De La Plata ◽  
La Plata ◽  
Floating Vegetation

The southernmost record of the neotropical genus Xenicola is documented. An apparently tiny population of X. dohrni, a species described long ago from southern Brazil without other published records, lives at the shore of the Río de la Plata, 1000 km further south. Perhaps it has been established there by means of floating vegetation. The acoustic communication of this species is also very interesting: The male produces with its minuscule tegmina brief signals with a carrier frequency range between 80 and 100 kHz. The female responds, and the male modifies its song when engaged in a duet. It modifies it further, when the female responds from very close. The paper includes a review of the records of Xenicola species on biodiversity observation platforms. 

scholarly journals Vascular plant species of the floating vegetation rafts from the Río de la Plata (Argentina)

Rodriguésia ◽  
2018 ◽  
Vol 69 (4) ◽  
pp. 1965-1972
Author(s):  
Elián Leandro Guerrero ◽  
Federico Lisandro Agnolin ◽  
Mariana Benedictto ◽  
Diego Gambeta ◽  
Felipe Andrés Suazo Lara ◽  
...  
Keyword(s):  
Plant Species ◽  
Vascular Plant ◽  
Sensu Stricto ◽  
Point Of View ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Economic Point ◽  
La Plata ◽  
Floating Vegetation ◽  
Conservation Plans

Abstract In South American rivers, Eichhornia crassipes and other floating plants intertwine and form floating rafts commonly known as "camalotales" which are especially abundant during flooding periods. During extraordinary floods, hectares of floating mats are drifted by the Plata Basin Rivers. In the Río de la Plata several reports suggest that many animal and plant species from subtropical latitudes colonizes the area through these large rafts. These episodes are very important from the economic point of view because they cause several troubles to navigation and other activities. On the other hand, benefits to biodiversity are conspicuous, and many authors consider this process vital to the Río de la Plata wetlands and forests. However, there is scarce knowledge about Eichhornia rafts plant species composition. With the aim of creating an exhaustive list of the flora of the Eichhornia rafts, we visited the Río de la Plata coast during a massive Eichhornia rafts arrival. Thirty-two plant species were recorded in three different plant assemblages: Eichhornia rafts sensu stricto, floating reeds (canutillares) and embalsados. In front of this unexpected we emphasize the need to include this phenomenon in regional biodiversity conservation plans.

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