• 1445-1405 BC

    12 plagues of Egypt

    And all the water of the Nile became blood. The fish of the Nile died and the river smelled so foul that the Egyptians could no longer drink its waters. Then there was blood throughout the land of Egypt, Bible (Exodus, 7, 20-21)

  • 1525

    Ciguatera poisoning in Garcia Jofre de Loaísa expedition

    During the Spanish expedition of Garcia Jofre de Loaísa to the Moluccas Islands in 1525, there was an intoxication of the crew, quoted by Andrés de Urdaneta: “In the last days of October 1525 the seven ships were anchored on the equatorial island of San Mateo. One day he took fish that looked like corvine, as big as a 20-pound salmon, and all those who ate at the captain’s table were sick, and it was on this island that a very beautiful fish caught, which he called beaked, and the captain-general invited some of the captains and officers of the King and all those who ate the beaked fell ill in the cabins, who went without feeling, we thought they died”. One year after the stay in San Mateo (Annobon), none of the hypothetical diners at the captain’s table remained alive on the expedition, including Captain Juan Sebastian Elcano. The beaked or barracuda is a large fish, typical of the tropical reefs, whose ingestion can produce in the human the ciguatera, disease originated by the toxins contained in certain microscopic algae, harmless for the fish but dangerous for the human species.


  • 1530

    Cabeza de Vaca

    Alvaro Núñez Cabeza de Vaca mentions in “Shipwrecks” that the natives of the Mexican and Western coast of Florida knew the dangers of consuming fish at certain times of the year, perhaps coinciding with episodes of red tides. It is now known that in this zone there are proliferations of toxic dinoflagellate Karenia brevis.

  • 1676

    First marine microorganisms under a microscope

    First descriptions of marine microorganisms by Anton van Leeuwenhoek using an optical microscope.


  • 1703

    Discovery of diatoms

    An unknown Englishman was the first to observe and illustrate diatoms (Tabellaria flocculosa) found in the roots of an aquatic plant.

  • 1753/1773

    Description and nomenclature of the first dinoflagellates

    In 1753, the earliest modern dinoflagellates were described by Henry Baker as “little animals that cause bright light in sea water”, while Otto Friedrich Müller was the first to name them in 1773. The term derives from the Greek words dinos, which means twist and flagellum, whip, referring to its characteristic rotational movement.


  • 1793

    First documented case of death by biotoxins

    First report of poisoning deaths due to seafood consumption on the west coast of the United States, described by British Columbia Captain George Vancouver in “A Voyage of Discovery to the North Pacific Ocean, and Round the World”.

  • 1799

    Baranoff expedition

    On the shores of Alaska, the Russian Baranoff expedition lost 100 men from mussel intoxication.


  • 1832

    Charles Darwin, Beagle

    Charles Darwin describes a red tide on the coast of Brazil and other episodes on the coast of Chile. “March 18th. We sailed from Bahia. A few days later, at a short distance from the Abrolhos islands, I noticed that the sea had acquired a reddish brown tint. Viewed with a magnifying lens, the whole surface of the water seemed covered with bits of chopped hay and whose limbs were frayed. They are small filamentous algae in cylindrical packages containing about fifty or sixty of these little plants. Mr. Berkeley warns me that they belong to the same species (nowadays Trichodesmium erythraeum) as those found in a large expanse of the Red Sea, and which have given this name to that sea. The number of these plants must be infinite; Our ship went through several bands of them, one of which was about ten meters wide, and which, judging by the discoloration of the water, must have been at least two and a half miles long”.

  • 1869-70

    Jules Verne

    Jules Verne publishes “Twenty Thousand Leagues Under the Sea”, where he describes bioluminescence in the sea: “The Nautilus floated among a phosphorescent layer that in the middle of the night glowed much. It was produced by thousands of luminous little animals, whose brilliance grew as it slid over the metallic hull of the apparatus. In the middle of the luminous layers, then, certain lightning flashes, as if they were jets of molten lead in a fiery furnace, or metallic masses heated to hot red (…)”.


  • 1903

    Illustrations of dinoflagellates

    First illustrations of marine dinoflagellates in Galicia, by Dr. Carús Falcón in The Mysteries of Nature. Research on the micro-plankton of the Arosa Estuary.

  • 1918

    Hematotalasia in the Ría de Vigo

    First scientific record of a red tide in the Ría de Vigo, by Sobrino-Buhigas, “La purga de mar or hematotalasia”. This red tide took place in the year 1916 and was illustrated in a painting of his brother, the artist Ramon Sobrino.


  • 1959

    Publication of “Structure and dynamics of the sea purge in the Ria de Vigo”

    Ramón Margalef published in the 50’s his studies on the composition and variations of phytoplankton populations in the Ría de Vigo. His publication “Phytoplankton of the Ria de Vigo” describes for the first time the phenomenon of succession in the phytoplankton communities in relation to environmental factors. He also published his results on the study of the phenomenon of the sea purge in the Ria de Vigo.

  • 1976

    Massive poisoning by PSP

    Paralytic shellfish poisoning (PSP) in France, Italy, Switzerland, Germany and Spain with bivalves from the Galician estuaries. At least 176 people received hospital care, there were no fatalities.


  • 1977

    Phytoplankton monitoring in Galicia

    Monitoring of potentially toxic phytoplankton in mollusk production areas and presence of PSP toxin in bivalve mollusks begins in Galicia (Oceanographic Center of Vigo-IEO).

  • 1981

    Discovery of diarrheal toxins in Galicia

    Mussels from the Rías Altas (Ares-Betanzos) caused gastroenteritis in 5,000 people throughout Spain. The causative agent was the toxins produced by a dinoflagellate (Dinophysis spp).


  • 1992

    Foundation of INTECMAR

    Initially called the Center for Quality and Control of the Marine Environment (currently INTECMAR) and dependent on the Xunta de Galicia, it has since followed the monitoring of oceanographic conditions, biotoxins and marine phytoplankton of the Galician estuaries.

  • 1993

    DSP and PSP poisoning in A Coruña

    At the end of summer of 1993 some residents of the village of Lariño (A Coruña) were intoxicated after eating mussels of rock. The symptoms were typical of neurotoxins: some suffered diarrhea, having to be even hospitalized. The mussels were contaminated with diarrheal and paralyzing toxins (DSP and PSP) due to toxic proliferations that affected all the Galician estuaries in the summer and autumn (5 months).


  • 1994

    Discovery of amnesic toxins in Galicia

    It was the first time that these types of toxins were detected in the Atlantic NE produced by diatoms. It happened in late summer 1994 in the Ria de Muros and toxins were detected in mussels from bateas after a proliferation of Pseudo-nitzschia australis.

  • 2014

    Intoxication by ASP in Galicia

    In the summer of 2014, two people visited the Hospital do Barbanza (Ría de Arousa) with symptoms of confusion and memory loss. They had ingested mussels contaminated with amnesic toxins (ASP), which they bought directly from a producer. They were probably from A Pobra (Ría de Arousa), on dates when it was forbidden to sell because of amnesic toxins.