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Antofagasta Bay is characterized by having a high primary productivity due to the presence of the cold Humboldt Stream. However, due to the current global climate change, also the previously generated biodiversity patterns are changing. The aim of the present study was analysing Antofagasta Bay in order to determine the existence of correlations between optical, i.e., spectral, properties recorded through remote sensing on the one hand, and the presence of dinoflagellates and zooplankton, on the other. The studies were done during two periods, i.e., in February 2019 and February 2020. The results revealed the existence of three main groups of sites: a first group comprising sites sampled in February 2019, with high Band 3 and Band 4 reflectance, high chlorophyl values, and high abundances of Dinophysis and copepods; a second group combining four sites visited in February 2019, with high Gymnodinium and Ceratium , high reflectance in Band 1, Band 2, Band 5, Band 6 and Band 7, and low zooplankton abundance; and finally a third group encompassing all sites sampled in 2020, with high Prorocentrum abundance, and low zooplankton abundance, as well as low reflectance. A similar situation with regard to zooplankton and optical properties was earlier reported for Chilean Patagonian lakes. Resumen: La Bahía de Antofagasta se caracteriza por tener una alta productividad primaria debido a la presencia la corriente fría de Humboldt. Sin embargo, debido al cambio climático global actual, también están cambiando los patrones de biodiversidad generados anteriormente. El objetivo del presente estudio fue analizar la Bahía de Antofagasta para determinar la existencia de correlaciones entre propiedades ópticas, es decir, espectrales, registradas por teledetección por un lado, y la presencia de dinoflagelados y zooplancton, por otro. Los estudios se realizaron en dos períodos, es decir, en febrero de 2019 y febrero de 2020. Los resultados revelaron la existencia de tres grupos principales: un primer grupo que comprende los sitios muestreados en febrero de 2019, con alta reflectancia de Banda 3 y Banda 4, altos valores de clorofila y abundancia elevada de Dinophysis y copépodos; un segundo grupo que combina cuatro sitios visitados en febrero de 2019, con alto Gymnodinium y Ceratium , alta reflectancia en Banda 1, Banda 2, Banda 5, Banda 6 y Banda 7, y baja abundancia de zooplancton; y finalmente un tercer grupo que abarca todos los sitios muestreados en 2020, con alta abundancia de Prorocentrum y baja abundancia de zooplancton, así como baja reflectancia. Una situación similar con respecto al zooplancton y las propiedades ópticas se informó anteriormente para los lagos patagónicos chilenos. [ABSTRACT FROM AUTHOR]

The effects of climate change and the severe anthropization of local river systems have contributed to the alteration of ecological processes, affecting the water quality in these systems and thus generating conditions for the emergence of algal species. In this context, the object of the present study was to evaluate the potential of remote detection techniques to obtain a spectral characterization of D. geminata under controlled laboratory conditions. This would provide the basic information for the design and implementation of a monitoring and early warning system. D. geminata cells obtained from two southern Chilean river systems were cultivated in the laboratory and analysed using hyperspectral techniques to construct their spectral signatures. The results showed the feasibility of distinguishing between the presence and absence of D. geminata when it occurs in association with other diatom present in the environmental. The results could be the first step towards the design and implementation of a monitoring and early warning system to facilitate existing inspection activities. [ABSTRACT FROM AUTHOR]

Northern Chilean Patagonia has numerous pristine lakes associated with Nothofagus and Araucaria araucana forests. The present study looks at optical properties in visible, close, and medium infrared wavelengths in mountain lakes located in Huerquehue National Park. These lakes have associated Nothofagus and Araucaria araucana native forests with glacial origin. The satellite results revealed high reflectance values in Los Patos Lagoon to B5, B6, and B7 Landsat-8 satellite bands. This lagoon is the most ephemeral pool located within A. araucana forest, whereas Tinquilco Lake has B5, B6, and B7 low reflectance values, which would be due to the presence of Nothofagus forest and probable human intervention in its surrounding basin. Whereas Angelica, Del Sacrificio, Chico, Los Condores, Las Mercedes, Olvidada, Toro, and San Manuel lagoons have low B3, B4, B5, B6, and B7 reflectance values, which would be because of the presence of native forest in their surrounding basin, and that all of these ecosystems are permanent. These differences, in spite of the oligotrophy, would be associated with surrounding vegetation and geological characteristics of studied sites. [ABSTRACT FROM AUTHOR]

Northern Chilean Patagonia has numerous pristine lakes associated with Nothofagus and Araucaria araucana forests. The present study consists of a study of optical properties in visible, close, and medium infrared wavelengths in mountain lakes surrounding Llaima Volcano - lakes that have associated Nothofagus and Araucaria araucana native forests with volcanic origins. The results revealed high reflectance values in Arcoiris Lagoon that has volcanic stones in its bottom, whereas the other lakes and lagoons have low reflectance values. These differences in spite of oligotrophy would be associated with surrounding vegetation and geological characteristics of studied sites. [ABSTRACT FROM AUTHOR]

Northern Chilean Patagonia has numerous pristine lakes associated with perennial native forests. The present study looks at optical properties in visible, close, and medium infrared wavelengths in mountain lakes of Alerce Andino National Park (41°S). These lakes have associated Nothofagus and Fitzroya cupressoides native forests of glacial origins. The results revealed high reflectance values for B1 and B3 for Chaiquenes, Triangulo, and Sargazo lakes located within Nothofagus and F. cupressoides native forest; Precipicio Lagoon has high B3, B4, B5, B6, and B7 reflectance values, perhaps due to granite surroundings; and the remaining 18 lagoons have relative low reflectance values for all bands, probably due to the predominance of Cupressaceae forest and mountains that make access difficult. These differences are associated with surrounding vegetation and geological characteristics of the studied sites. [ABSTRACT FROM AUTHOR]