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; MP, mixotrophic phytoplankton including eukaryotic diatoms
and prokaryotic cyanobacteria; pZ, protozooplankton; NYA, not yet assigned. See text and Fig.
1 for further explanations.
in a photo-osmo-phago-mixotroph the
mixoplankton - functional group; these
are primarily planktonic protists.
The mixoplankton HABs are then
broadly classified into constitutive and
non-constitutive mixoplankton. Here,
the constitutive mixoplankton (CM) are
HAB species which have innate photosynthetic capabilities; these include
various species from the Dinophyceae
(e.g., Alexandrium minutum, Karenia
brevis, Karlodinium veneficum), Raphidophyceae (e.g., Chattonella marina,
Heterosigma akashiwo) and Haptophyta (e.g., Chrysochromulina leadbeateri,
Prymnesium parvum) groups.
The non-constitutive mixoplankton
(NCM) are those that need to acquire
their obligate phototrophic capabilities from either generic species (generalist non-constitutive mixoplankton,
GNCM) or specific species (specialist
non-constitutive mixoplankton, SNCM).
There are no known HAB GNCMs; GNCMs comprise various ciliates, such as
Strombidium and Laboea species [8].
The SNCMs are further divided into
those that retain plastids and parts of
the prey (plastidic SNCM, pSNCM) and
those that maintain endosymbionts
(endosymbiotic mixoplankton). The
well-known HAB Dinophysis fall within
HARMFUL ALGAE NEWS NO. 67 / 2021
the pSNCM group while the HAB Pfiesteria piscida with their reduced endosymbiont fall within the r-eSNCM group.
Dinophysis acquires its plastids from
the SNCM ciliate, Mesodinium, which in
turn acquires its plastids from CM cryptophytes such as Teleaulax. Thus, SNCM
species always depend on the availability of other species for acquired phototrophy while CMs have no such restriction on their growth. Furthermore, the
conditions of growth effects the longevity of acquired plastids in NCMs and
thus the components of the food chain
are closely coupled.
Fig. 2 presents preliminary results
from assigning this functional group
classification to the 190 HAB species
currently recorded in the IOC-UNESCO
list. The not yet assigned (NYA) group
represents HABs within the Dinophyceae group which are known to be
mixotrophic by virtue of being photoosmo-heterotrophic but we have not
found any published records evidencing their capability (or, otherwise) to
engage in phagotrophy. The primary
reason behind allocating NYA to these
groups rather than mixotrophs is the
presence of various well-known mixoplanktonic species within the same genus (e.g., the CM Alexandrium catenella
vs the NYA A. hiranoi; the CM Karenia
brevis vs the NYA K. cristata).
Phagotrophy has a direct consequence for trophic dynamics, with the
removal of competitors and potentially
also predators by the collective action
of high abundance blooms of HAB species. Phagotrophy also provides nutrients which, according to traditional
inorganic nutrient analysis, may otherwise be considered as limiting. The
consumption of bacteria, for example,
appears common. The traditional food
web considers bacteria as a competitor
for nutrients with phytoplankton; indeed, nutrient stressed phytoplankton
release increased amounts of organics that promote bacteria growth in a
positive feedback loop [10]. Protozooplankton then control the dynamics of
the interaction (Fig. 3). According to
the mixoplankton paradigm [3-4], the
protists are not in competition with
the bacteria, but de facto farm them to
acquire nutrients (Fig. 3). The consequential dynamics of the growth of the
phototrophic protist (phytoplankton
in the traditional scenario; mixoplankton under the mixoplankton paradigm)
differs greatly (Fig. 3),
Labelling HAB species as mixoplankton, or otherwise, has obvious important consequences for how we consider factors affecting the growth and
demise of these organisms. It also then
affects how those responsible for monitoring water quality and ecosystem services may view the ecosystem. In short,
assuming the activity of HAB species
aligns with phytoplankton needing
light and inorganic nutrients, can be
considered for many if not most species
as inappropriate. That Chrysochromulina is a mixoplankton, and grows to such
perfusion around salmon farms [11] is
perhaps no coincidence.
For more about mixoplankton,
please see the article about the recent
Mixoplankton International Conference
in this edition of HAN, and also visit
www.mixotroph.org
Acknowledgements
This work was funded by the project
MixITiN. This project has received funding from the European Unions Horizon
2020 research and innovation programme under the Marie SkłodowskaCurie grant agreement No 766327.
5
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