Detection of Phytoplankton Temporal Anomalies Based on Satellite Inherent Optical Properties: A Tool for Monitoring Phytoplankton Blooms.

Jesús Antonio Aguilar-Maldonado,Eduardo Santamaría-Del-Ángel,Adriana Gonzalez-Silvera,María Teresa Sebastiá-Frasquet

doi:10.3390/s19153339

Jesús Antonio Aguilar-Maldonado, Eduardo Santamaría-Del-Ángel + Show 2 more

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https://doi.org/10.3390/s19153339

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Abstract

The baseline of a specific variable defines the average behavior of that variable and it must be built from long data series that represent its spatial and temporal variability. In coastal and marine waters, phytoplankton can produce blooms characterized by a wide range of total cells number or chlorophyll a concentration. Classifying a phytoplankton abundance increase as a bloom depends on the species, the study area and the season. The objective of this study was to define the baseline of satellite absorption coefficients in Todos Santos Bay (Baja California, Mexico) to determine the presence of phytoplankton blooms based on the satellite inherent optical properties index (satellite IOP index). Two field points were selected according to historical bloom reports. To build the baseline, the data of phytoplankton absorption coefficients () and detritus plus colored dissolved organic matter (CDOM) () from the generalized inherent optical property (GIOP) satellite model of the NASA moderate resolution imaging spectroradiometer (MODIS-Aqua) sensor was studied for the period 2003 to 2016. Field data taken during a phytoplankton bloom event on June 2017 was used to validate the use of satellite products. The association between field and satellite data had a significant positive correlation. The satellite baseline detected a trend change from high values to low values of the satellite IOP index since 2010. Improved wastewater treatment to waters discharged into the Bay, and increased aquaculture of filter-feeding mollusks could have been the cause. The methodology proposed in this study can be a supplementary tool for permanent in situ monitoring programs. This methodology offers several advantages: A complete spatial coverage of the specific coastal area under study, appropriate temporal resolution and a tool for building an objective baseline to detect deviation from average conditions during phytoplankton bloom events.

Highlights

Blooms are proliferation events of phytoplankton species, such as dinoflagellates, diatoms and cyanobacteria in aquatic ecosystems [1]
We propose the application of the inherent optical properties (IOPs) index, based on the use of time series standardized anomalies, to build a baseline of phytoplankton and detritus plus colored dissolved organic matter (CDOM)
As time goes by the data base of aphy,generalized inherent optical property (GIOP) and adCDOM,GIOP will be increasing with new data, and the baseline can be modified

Summary

Introduction

Blooms are proliferation events of phytoplankton species, such as dinoflagellates, diatoms and cyanobacteria in aquatic ecosystems [1]. They can last less than 24 h (fast blooms), can last for several days [2] or last for weeks [3]. Chlorophyll a (Chla) has been widely used as a proxy for phytoplankton biomass in both remote sensing and in situ monitoring programs [8]. Other phytoplankton properties can be monitored from remote sensing and be applied to the study of blooms. The use of IOPs from remote sensing technology may allow long-time monitoring at moderate- or high-spatial resolution and high-temporal resolution [18,19,20], which is essential to build the baseline

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