An online platform (GEE App) for Trophic State Index
monitoring of inland waters in Latin America
Fig. 1. a) The dark gray region shows the Paraná River Basin in Brazil; b) Water masses within
Paraná River Basin palette according to the Chl-a concentration average for 2020. The red
rectangle indicates the Billings Reservoir taken as an example for the GEE App (see Fig. 2).
Human activities on a global scale have
significantly contributed to the change
in quality of water bodies caused by
increasing nutrients levels. In these
circumstances, algae have proliferated
rapidly and their concentrations are
above normal values. The lack of in situ
data in Latin American countries limits
the capacity of water quality management due to the paucity of information
about the current status of surface waters. In this scenario, remote sensing
and cloud computing techniques are
fundamental tools to deliver precise and
quick indicators of algal bloom (AB) occurrence and Trophic Levels over large
areas, supporting decision-makers and
management actions.
Last year, in collaboration with several researchers, a project to develop a
tool that maps ABs over the main water
bodies and reservoirs in Latin America
was approved by Google Earth Engine
(GEE) [1] and Earth Observation Data
Science (EO) [2]. So far, the proposed
methodology uses Sentinel-2 images
corrected for atmospheric and sun-glint
effects to generate an image collection
of the Normalized Difference Chlorophyll-a Index (NDCI) [3] for the entire
time-series (August 2015 to present) of
HARMFUL ALGAE NEWS NO. 67 / 2021
a given area. The NDCI retrieved from
the imagery are compared with chl-a
measured in situ with a time window
of + 2 days for match-ups. NDCI is used
to estimate chl-a concentration by applying a non-linear fitting model, and
is also used to classify every pixel into
5 classes of Trophic State Index (Oligo,
Meso, Eutrophic, Super and Hypereutrophic) [4] based on a tree-decision
model. Once the approach is developed and validated using pilot sites, the
method will be transferred to stakeholders at several levels to provide AB
information for the main water bodies/
reservoirs in Latin America.
In this article, we report the first
results for the Tiete River Basin, one
of the Paraná River Basins main tributaries, located in the State of São Paulo,
Brazil (Fig. 1). Water in large urban
areas in São Paulo is supplied by a variety of reservoirs. The rapid urbanization and industrialization process led
to high nitrogen and phosphorus concentrations in surface waters and consequently degradation of water quality
and eutrophication. For example, the
Billings reservoir, which is located in
the upstream Tietê basin, has faced serious water pollution problems due to
the expansion of urban slums with no
sewage or solid waste collection system. As a result, high chl-a and TSI levels were often observed throughout the
past year (Fig. 2).
The use of cloud computing (GEE)
to process all Sentinel-2 imagery and
generate the NDCI collection, allows
for quick access to the chl-a and TSI
(Trophic State Index) levels for any
water body within the study area (Paraná River Basin, Fig. 1), which includes
several reservoirs and dams, such as
Itaipú, Três Marias, Cantareira System
and others.
More importantly, all of this information will be freely accessible for the
general public via an Earth Engine APP
(Fig. 2) that allows personalized evaluation of a given water mass that can either be chosen from a list or drawn by
the user on the map canvas. The APP is
currently in development and soon will
be released in the GEE APP gallery. The
user will be able to define date range,
ROI (Region of Interest), time-series
charts (either NDCI or Chl-a) and TSI
area charts (% class area), and save
these plots as texts or image formats.
For the projects following activities,
we plan to improve the APP and release
it on-line within the following weeks.
We will also extend the NDCI collection to other important South America
regions, such as Uruguay, Argentina,
and North-eastern Brazil. However, this
extention depends on the availability
Continued at page 17
Fig. 2. Screen grab of the current version
of the experimental GEE App. a) Display of
maps and classifications; b) User interface,
where the user can pick date range, ROI and
select the products (NDCI, Chl-a and/or TSI)
to be displayed as charts (c and d).
13
Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 67 - April 2021 www.ioc-unesco.org/hab SHIOHIGARI and PSP toxins in Japan: Initiatives to save traditional recreatio nal clam picking Shiohigari has been enjoyed by people in Japan for centuries, as depicted in the Japanese a
Fig. 2 Clamming parks in Osaka Prefecture (Modified from a digital map of The Geospatial Information Authority of Japan) ingly, they had developed the exchange system to secure viability of their operations before 2002 when PST exceeding the regulatory limit were first detected in clams from seas a
Fig. 4 System of exchanging clams which secure food safety at Tannowa clamming park (Modified from [3} of visitors to clamming parks has now recovered. This is a success story of how to mitigate socio-economic impact on recreational clamming in Osaka prefecture due to PST. Thanks to the initiatives
HABs and the Mixoplankton Paradigm Mixotrophs are defined as organisms that are able to use photo-autotrophy and phagotrophy or osmotrophy to obtain organic nutrients [1]. It is notable that all phototrophic protists are potentially mixotrophic if only through expression of osmotrophy enabled by the
Fig. 2. Indication of proportion of IOC-UNESCO HAB species [6] assigned to each of the HAB plankton functional groups according to key in Fig.1 compiled by cross-reference to a database on mixoplankton species. CM, constitutive mixoplankton; pSNCM, plastidic specialist non-constitutive mixoplankton;
Fig. 3. Schematics and model simulation outputs run under the traditional paradigm (left) versus the mixoplankton paradigm (right). See text for explanation. B bacteria; Phyto phytoplankton (non-phagotrophic phototroph); μZ protozooplankton; CM constitutive mixoplankton (photophago-trophic); DIM
Tiny cells with a big impact: An unexpected bloom in the mid-Atlantic Fig. 1. a) Bongo nets fouled with the brown mucilaginous plankton. b) Dark and gelatinous content of the plankton nets scraped into a sample tray. Since 1992, the US NOAA Ecosystem Monitoring (EcoMon) cruises survey the Northeas
Fig. 3. Scanning electron micrographs of frustules in valve view of Thalassiosira mala. Note the single eccentric strutted process (black arrow), the ring of marginal strutted processes (arrowheads) and the single labiate process (white arrow) located within the ring of marginal strutted processes s
Acknowledgements We are grateful to Kyle Turner for helpful discussions regarding the fall 2018 EcoMon cruise and to Dr. Irene Andreu for SEM assistance. Dr. Paul E. Hargraves provided some insights on diatom taxonomy. We acknowledge the dedication of the crew of the R/V Sharp during a particularly
First report of an Ansanella granifera bloom in Cuban waters, Caribbean region Fig. 1. Map of the study area showing the location where the dinoflagellate bloom o ccurred in southeastern Cuba. Harmful Algal Blooms (HABs) have been associated with fish and shellfish kills, ecosystem damage, human
Fig. 3. Light microscopy images of fixed cells of Ansanella granifera. 4). Ansanella granifera is a dinoflagellate belonging to the family Suessiaceae (order Suessiales) that was recently described from Korea [5]. To our knowledge, the occurrence in waters from southeastern Cuba represents the firs
Dolichospermum spiroides blooms in a man-made lake in Sarawak, Borneo pond in Serian, Sarawak, and co-existed with a Microcystis bloom. However, the species and cell density for both genera were not recorded [3]. This is the first documented report of D. spiroides in Sarawak waters. The occurrence
An online platform (GEE App) for Trophic State Index monitoring of inland waters in Latin America Fig. 1. a) The dark gray region shows the Paraná River Basin in Brazil; b) Water masses within Paraná River Basin palette according to the Chl-a concentration average for 2020. The red rectangle indica
Remote sensing of recurrent cyano HABs in Patos Lagoon, Brazil Fig. 1. Map of Patos Lagoon (southernmost part of Brazil) taken from [7]. Black circles indicate the four sites chosen forNDCI values retrieval [4]. Every austral summer, dense surface growth and accumulations of cyanobacteria threaten
ation promoting the prevalence and duration of cyanoHABs. More detailed information will be published soon adding modeling tools to locate dominant cyanoHAB accumulation sites within the PL, and their potential exportation to the ocean. Future studies are needed to discriminate between local effects
Blooms of Akashiwo sanguinea (Dinophyceae) in a tropical estuary in northeastern Brazil We report an inter-annual bloom of the unarmored dinoflagellate Akashiwo sanguinea in a pristine estuary (Figure 1F) in Brazil. The estuarine section of the Serinhaém River, Camamu Bay is a species-rich ecosystem
can affect the entire structure of a community due to changes in composition due to outcomes of biotic interactions with one species being benefited while another one is harmed. The spatial location of SE10 within an area of potential disturbance driven by urban tributaries alters ecological stoichi
Can artisan fishermen help to prevent HABs intoxication? A science communi cation project in Rio de Janeiro, Brazil Fig. 1. Geographic distribution of the main harmful microalgae genera in Brazilian coastal waters. These genera may induce different poisoning syndromes: amnesic shellfish poisoning (
Authors Raquel AF Neves, Júlia Torres, Nathália Rodrigues & Clarissa Naveira, Graduate Program in Neotropical Biodiversity (PPGBIO), Research Group in Experimental and Applied Aquatic Ecology, Federal University of the State of Rio de Janeiro (UNIRIO), Avenida Pasteur 458-307 Rio de Janeiro- RJ, CEP
The VIII Workshop the Group HarmAlfonso Vidal (Colombia). Their of dediconsider it urgent to finalize The VIIIofWorkshop of the Group Harmful Algal Blooms the Caribbean (ANCA) of a regional ful AlgalIOCARIBE Blooms of (Intergovernmental the Caribbean catedOceanographic work contributedCommission sig
Aotearoa/New Zealand Japan collaboration strengthened through HAB research at Cawthron Institute the 16th Young Researchers Award from the Japanese Society of Phycology for his research on harmful algae in Japan. Acknowledgements The collaboration between New Zealand and Japan has been continued
ANNOUNCEMENT: The International Phytoplankton Intercalibration The International Phytoplankton Intercalibration (IPI) Proficiency Testing scheme in abundance and composition of marine microalgae programme 2021 is now open for registration for 2021 through www.iphyi.org. The schedule for 2021 and all
The 19th International Conference on Harmful Algae 2021 (ICHA2021) is going virtual! We appreciate the responses that many of you provided in the recent survey which indicated that 85% of respondents will participate in a virtual meeting. The abstract submission deadline is 9 April 2021. Details on
In memoriam Maria Esther Angélica Meave del Castillo (1960-2020) María Esther Meave (who also received the nickname Teté or Tey by many of her friends) was born in Mexico city, Mexico (September 5th, 1960) and passed away on December 6th, 2020, after contracting COVID-19. She earned her Master and
Leif Bolding, graphic designer and webmaster at the Department of Biology, University of Copenhagen, Denmark, has been an unsung hero of Harmful Algae News. Working behind the scenes since 2000 as responsible for the layout of each issue. Leif retires at the end of April 2021. He will have plenty of