MAP Technical Reports Series No. 106 UNEP

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Gymnodinium catenatum has already been found in the Mediterranean sea: in a
Tyrrhenian coastal lagoon (Carrada et al., 1988) and on the Spanish Mediterranean coast (Bravo
et al., 1990). Only G. catenatum cells of Spanish coast produce PSP, but ichthyotoxic effects
are not reported (see chapter 7).
In the Adriatic sea, along the coast of Emilia-Romagna, Gymnodinium sp., at first
identified as G. corii, caused a green tide in 1976 and another in 1977 (Viviani, 1977a; 1981),
which was named "green soup" by the press (Goldoni, 1976). This phenomenon was repeated
in November of 1984, and covered the sea from the Marche to Veneto (Centro Studi Ricerche
Risorse Biologiche Marine Cesenatico, 1984; Regione Emilia-Romagna, 1984). In research
carried out in 1976-77 on potential ichthyotoxicity it was possible to demonstrate that the
phenomenon of fish death was due to an anoxic condition (Viviani et al., 1985). In 1988, the
same species of Gymnodinium indicated as Gymnodinium sp., caused a similar tide which
lasted for three months without harmful effect on invertebrates and fish (Centro Studi Ricerche
Risorse Biologiche Marine Cesenatico, 1988; Regione Emilia-Romagna, 1988).
In 1982-83 and 1985, green tides (3,000,000 cells/litre) were observed in the Bay of
Vilaine and Marennes (Lassus, 1984).
Genus ALEXANDRIUM Halim (= GONYAULAX)
Alexandrium monilata (= Gonyaulax monilata), a common dinoflagellate in the Gulf of
Mexico, produces a substance toxic for fish (Gates and Wilson, 1960; Aldrich et al., 1967), but
it does not affect the chick, the mouse or other warm-blooded animals (Ray, 1971). The oysters
of the Gulf of Mexico do not filter water when exposed to A. monilata. Clemons et al. (1980) have
tried to purify the toxin, following the toxicity against German cockroaches and haemolytic
activity. In their experiment, the toxicity has been found in the water-soluble fraction of a
molecular range over 100,000.
Alexandrium tamarensis from the English coast has caused death in aquatic animals,
whereas that from the Atlantic coast of Canada has never produced such effects (Ray, 1971).
In Mediterranean, in the eastern lagoon of Alexandria bay outbreaks of red tides caused
by Alexandrium minutum are recurrent summer phenomena since first observed in 1958 (Halim,
1960). Fish-kills occur, caused by clogging of the gills, but toxins are not reported (Halim, 1989).
Gonyaulax polyedra indicated as ichthyotoxic (Ballantine and Abbott, 1957; Schradie
and Bliss, 1962; Reish, 1963), and responsible for young oyster mortality (Paulmier, 1977),
caused in the Adriatic sea (Emilia-Romagna coast and Spalato Bay) "easy fishing" and mortality
of fish and molluscs. This has been attributed to O 2 deficiency (Viviani, 1977a; Marasovic and
Vukadin, 1982).
Genus GYRODINIUM
In the blooms of Gyrodinium aureolum, closely connected to Gymnodinium
nagasakiense of the Pacific (which in Japan causes fish kill), mortality of fish and salmon farms
on the Irish, Welsh and Scandinavian coasts, and of invertebrates after 1966, have been
described (Tangen, 1977; Ottway et al., 1979; Whiddows et al., 1979; Roberts et al., 1983). At
the end of the 1980s it has been highlighted that the ichthyotoxic effect, at the level