Global Harmful Algal Blooms


PROJECT TITLERolEof Mixing on phytoplankton bloom initiation, maintenance and DIssipation in the Galician RíaS    

Acronym: REMEDIOS  

Timeframe:December 2016-December 2020 

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Principal Investigator: Beatriz Mouriño-Carballido

Address: Edificio Torre CACTI, Planta1ª, Laboratorio 100. Campus de Vigo. Universidade de Vigo, 36310 Vigo, Spain

Phone: +34-986-818788

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Participants: Universidad de Vigo (Spain), Instituto Español de Oceanografía (Spain), Instituto de Investigaciones Marinas-CSIC (Spain), Ifremer, Brest (France), University of Southampton (United Kingdom), SCRIPPS (USA), Linnaeus University (Swedden)


Project summary: High phytoplankton biomass is produced in the Galician Rías (NW Spain) due to fertilization by coastalupwelling and is responsible for the production of ∼250000 t year-1of Mediterranen mussels (Mytilusgalloprovincialis). Mussel aquaculture in Galicia represents 95% of the Spanish and 50% of the European mussel production, respectively. This successful industry is jeopardized every year by toxic phytoplankton blooms. Turbulent mixing is a key process as it controls water renewal time, which in turns determines the rate of exchange of nutrients, organisms and pollutants in the water column. Our current knowledge states that phytoplankton blooms occur when mixing provides the right levels of light and nutrients. However, due to methodological limitations, only very recently we have been able to quantify turbulence in the field. One of the most fascinating implications of this progress is the possibility to revisit classic models of phytoplankton ecology.

In 1953 Sverdrup proposed a simple conservation mass model, which used the depth of the mixed layer to predict the onset of the North Atlantic spring bloom. This model assumed a thoroughly mixed layer where turbulence was strong enough to distribute the phytoplankton cells evenly through the layer. Following trials, either to verify this hypothesis or to use its theoretical background, have generally forgotten this assumption and used the mixed-layer, defined as a layer homogenous in density, as the equivalent of a turbulent or mixing layer. Despite evidence suggesting that vertical mixing controls the annual cycle of biomass and composition of the phytoplankton community in the Galician Rías (NW Spain), its importance has been inferred from hydrographic conditions. So far, a specific study relating mixing and phytoplankton bloom formation is lacking. We propose to use the theoretical framework of the Sverdrup hypothesis to investigate phytoplankton bloom initiation, maintenance and dissipation in NW Spain. Special attention will be devoted to blooms of species from the genera Dinophysisand Pseudo-nitzschia, responsible for lengthy shellfish harvesting closures due to accumulation of diarrhetic (DSP) and amnesic (ASP) shellfish poisoning toxins, respectively, above regulatory levels. Previous studies in this region and in other areas in Western Europe indicate that these species frequently aggregate in “thin layers”. These layers, less than five meters thick and up to several km in horizontal extension, have important implications for the management of mollusc shellfish safety. Despite their socio-economic impact, the frequency of occurrence of thin layers of phytoplankton in the Galician Rías, and the role of mixing conditions in their formation and persistence remains unknown. 


REMEDIOS has a multidisciplinar project combining the expertise of different Galician and international (French and US) collaborations:


  1. Field observations of physical (including microstructure turbulence, cooperation with University of Southampton), chemical and biological variables (including nutrients uptake rates, cooperation with IFREMER; DNA RNA sequencing, Linnaeus University) in the Galician Rías and adjacent shelf using high vertical resolution instruments (including the IFREMER Fine Scale Sampler);
  2. Time series analysis of data collected by monitoring programs
  3. Empirical and numerical modeling (cooperation with SCRIPPS)


The main goal ofinvestigating the role of mixing in phytoplankton bloom formation in the Galician Rías will be pursued through the following specific objectives:


  • Objective 1: Describing theseasonal variability in the sources of turbulence and mixing magnitude;
  • Objective 2: Investigating the role of mixing on resource availability and phytoplankton bloom initiation, maintenance and dissipation;
  • Objective3: Describing the frequency and spatial distribution of thin layers of phytoplankton (TLP), and
  • Objective 4:Investigating the mechanisms responsible for the formation of TLP. 


Microstructure Turbulence Profiler deployed from the Research Vessel Krakhen (UVIGO) at the Ría de Vigo during the REMEDIOS-seasonal study (April 2017)

IFREMER Fine-Scale Sampler deployed from the Research Vessel Margalef (IEO)

at the Ría de Pontevedra during the REMEDIOS-TLP cruise (July 2018).

PROJECT TITLE:Selvagens Islands: an emerging "hotspot" of benthic harmful algal blooms


Time frame: March 2021 - February 2024

Principal Investigator: Pedro Reis Costa

Address: IPMA – Instituto Português do Mar e da Atmosfera, Av. Dr. Alfredo Magalhães Ramalho 6, 1495-165 Lisbon, Portugal

Phone: +351 213027169

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Other Key Persons:

Ana Amorim, MARE, Faculty of Sciences, University of Lisbon

Ester Serrão, CCMAR, Centre of Marine Sciences, Algarve University

Paulo Oliveira, IPMA-Portuguese Institute of Sea and Atmosphere

Carolina Santos, IFCN – Madeira Institute of the Forest and Natural Conservation

Neide Gouveia, SRMP – Madeira Regional Secretary of Sea and Fisheries


Main goals:

1) Investigate the origin, dynamics and fate of Gambierdiscus populations and of other BHAB species; 

2) Characterize the benthic-epiphytic microalgae communities, with particular attention to toxic species and assess the influence of environmental variables on their growth and toxicity.

PROJECT TITLE: Effects of climate changes on harmful algal and cyanobacterial blooms along the South Atlantic Ocean

Principal Investigator: Dr Márcio Silva de Souza

Address: Oceanography Institute (Federal University of Rio Grande - FURG), Italia Av., km-8, Carreiros, PO Box. 474, Rio Grande (Rio Grande do Sul), Zip Code: 96203-900

Tel/fax: +5553-32336737

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Other key persons: Dr. João Sarkis Yunes*

Dr. José Henrique Muelbert, Oceanography Institute (FURG), Italia Av., km-8, Carreiros, PO Box. 474, Rio Grande (Rio Grande do Sul), Zip Code: 96203-900; +5553-32336737


Objectives: Global warming effects, including the contribution of several anthropic activities such as the burning of fossil fuels and deforestation, can affect biomes and many physical and chemical features of the oceans. These effects over the dynamics and structure of phytoplankton (including cyanobacteria) are not yet well understood. However, shifts in duration and frequency of meteorological events have been associated with the increasing in harmful algal blooms (HABs) across many coastal regions worldwide. This proposal aims at assessing direct and indirect effects of climate changes over these phytoplankton blooms in the Atlantic Ocean (between 0º35ºS), taking into account environmental database analysis combined with notifications of HABs in Brazil and, also, further lab experiments with target species that form known HABs. As far as possible, there will be compiled physical, meteorological and hydrographical information as well phytoplankton data across the study region since 1970s. With this dataset, we will evaluate the spatial and temporal environmental variability linking to bursts of HABs. Also, we intend to build predictive models of these biological events for the Brazilian coast and to carry on bioassays with certain strains of HAB obtained in some local laboratories. Temperature and nutrient concentration (nitrate, phosphate) are the variables chosen a priori to be tested. This project is being conducted at the Oceanography Institute of the Federal University of Rio Grande (Brazil) as my pos-doc fellowship research.


Map of the study area showing (a) cities at the west margin of the Patos Lagoon system, where patches (two red ellipses) of Microcystis spp. have been notified; (b) patches of Microcystis spp. (inside of red circle) seen on 02 February 2017, retrieved from Landsat-8 Enhanced Thematic Map plus (ETM+;  Map of the study area showing (a) cities at the west margin of the Patos Lagoon system, where patches (two red ellipses) of Microcystis spp. have been notified; (b) patches of Microcystis spp. (inside of red circle) seen on 02 February 2017, retrieved from Landsat-8 Enhanced Thematic Map plus (ETM+;


PROJECT TITLE: International Collaborative Study for the Validation of a HILIC-MS/MS Method for Analysis of Paralytic Shellfish Toxins and Tetrodotoxin in Live Bivalve Molluscs


Scope: Global

Type: Research

Time frame: January 2017 to September 2018

Principal Investigator: Dr Andrew D. Turner

Address: Centre for Environment Fisheries and Aquaculture Science (Cefas)

Tel/Fax: +44 (0)1305 206636 / +44 (0)1305 206601

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Home page URL:

Other key persons: Dr Tim Harwood, Cawthron Institute, New Zealand

Objectives: The aim of this project will be to conduct a Collaborative Study of the LC-MS/MS method for PSP toxins in shellfish, using a suitable number of international toxin testing laboratories. The work will require active collaboration with organisations worldwide to validate the method, ultimately demonstrating its fitness for purpose for official control testing. The final achievement will involve the delivery of an extensive data set, the publication of the collaborative study and ultimately the delivery of a formally-approved official method of analysis. 

The project will be conducted through a collaborative study lead by Dr Andrew Turner at Cefas together in partnership with Dr Tim Harwood at Cawthron Institute. Additional guidance and collaboration will be provided by the EURLMB. The project has been discussed with international collaborators and is supported by Prof Ana Gago-Martinez Director of the EURLMB and James Hungerford, USFDA and Co-chair of AOAC Marine Toxin Task Force.


Implementation progress (November 6th, 2019): The PST by LC-MS/MS method ("Boundy Method") developed by Cawthron in collaboration with CEFAS in the UK has been published 25th October 2019. This method can supersede the Lawrence method as the confirmatory method for PST monitoring in New Zealand. We will continue to apply the Boundy method on all samples we receive for PST testing.


Andrew D. Turner, Monika Dhanji-Rapkova, Sum Y. T. Fong, James Hungerford, Michael J. Boundyand, D. Tim Harwood. (2019) Ultrahigh-Performance Hydrophilic Interaction Liquid Chromatography with Tandem Mass Spectrometry Method for the Determination of Paralytic Shellfish Toxins and Tetrodotoxin in Mussels, Oysters, Clams, Cockles, and Scallops: Collaborative Study. Journal of AOA C International Vol. 103, in press.




PROJECT TITLE: Predicting Risk and Impact of Harmful Events on the Aquaculture Sector


Scope: Regional

Type: Research

Timeframe: January 2018 to December 2020                                                              

Principal Investigator: Dr. Joe Silke

Address: Marine Institute, Oranmore, Co. Galway, Ireland

Tel/Fax: +353 91 387 200

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Other key persons:

Dr. Julie Maguire, Indigo Rock, Ireland; 
Prof.. Keith Davidson, SAMS, Scotland UK; 
Dr. Ruth Henderson, SeaFood Shetland, Scotland UK; 
Dr. Marc Sourisseau, IFREMER, France; 
Dr. Peter Miller, PML, England UK; 
Dr. Manuel Ruiz, IEO, Spain; 
Dr. Luz Maman, AGAPA, Spain; 
Dr. Luis Ferrer, AZTI, Spain.
Dr. Marcus Mateus, IST-Lisbon, Portugal


Objectives: The European aquaculture sector supports several North Atlantic coastal communities. The effects of harmful algal blooms (HABs) and microbial pathogens can have a massive impact on this sector. HABs negatively affect shellfish and finfish aquaculture operations through the rapid accumulation of biotoxins in farmed shellfish consumed by humans, and by killing entire stocks of farmed fish due to toxins, physical damage and deoxygenation. The estimated economic impact of HABs in EU waters may be as high as €919 million per year. Prevention of natural HABs is not possible but reliable early warnings may facilitate effective mitigation measures to safeguard public health and private business operations. 
The main objective of Project PRIMROSE is to provide a reliable standard, automated system for reporting and forecasting HABs and microbial events that impact aquaculture operations in European coastal waters. We will build on existing HAB early warning systems developed by our previous successful forecasting system during its predecessor, Project ASIMUTH (reported in a special edition of Harmful Algae, 2016).  New features of PRIMROSE will include; an expanded system for new fish- and shellfish-producing areas; improved HAB forecasts with greater resolution; a wider suite of parameters; an evaluation of the potential for mitigation; new index based risk assessments; and a valuable information service for policy makers, risk regulators, food safety authorities and the aquaculture sector, from Shetland to Canary Islands. The new forecast will include microbial risk (eg. E. coli, Norovirus, Vibrio) and environmental/ climate impacts, in addition to improved HAB predictions. 
PRIMROSE will benefit from improved spatial resolution, utilising new generation Sentinel data products for the main aquaculture production areas in France, Ireland, Portugal, Spain and the UK. Improved ASIMUTH-developed methodologies for producing HABs forecasts will result from operational oceanographic forecasts, downscaled regional hydrodynamic models, novel satellite data, phytoplankton/ biotoxin monitoring data and expert evaluation. PRIMROSE will upgrade the current HAB forecast service to the regional scale; providing mesoscale trans-national HAB and microbial risk information, risk assessments and knowledge exchange with the international user community. We intend to maintain close involvement/co-development with industry partners throughout the project to ensure maximum impact of the project outputs. 
New information from the Marine Strategy and Water Framework Directive monitoring programs; from a new generation of sensors aboard the Sentinel suite of satellites, and sensors collecting underway data aboard ferries, will also be utilised for the alert system. The aquaculture sector relies on sufficient early warning of harmful events, so that effective mitigation measures can be utilised. PRIMROSE will both develop a trans-national short- to medium-term risk forecast, and a long-term assessment of climate impact on HABs and pathogens.
The main objective of PRIMROSE is to provide a reliable standard, automated system for reporting and forecasting HABs and microbial events that impact aquaculture operations in European coastal (AA) waters.


 Asimuth domain illustrating the seaboard areas for which that HAB models and risk assessments were developed. From: Davidson et al. (2016). Preface: Forecasting the risk of harmful algal blooms. Harmful Algae 53: 1–7. 


Implementation progress (date):

User Location