MAP Technical Reports Series No. 106 UNEP

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7.2.2.4 DSP occurrence in the Mediterranean sea
In June 1989 the presence of Dinophysis fortii cells in hepatopancreas of mussels and
of lipid soluble toxin of DSP type in mussel tissue collected in the coastal water of the Emilia-
Romagna region (Boni et al., 1992) allowed to prove that the cause of certain cases of diarrhoea
in consumers of molluscs was not due to bacteria or virus but to biointoxication by DSP. This
phenomenon, brought to light by the Research Centre of Marine Biological Resources of
Cesenatico (University of Bologna, Italy), has subsequently extended over the coastal areas of
Marche, Abruzzo, Veneto and Friuli-Venezia Giulia. The existence of the enterotoxin in seafood
was initially revealed by the McFarren et al. (1965) method (biological test for the research into
fat-soluble algal biotoxins, according to the previsions of Italian Law) (Ministero della Sanità,
1978). In the second stage the Yasumoto et al. method (1984) was used. Although coloured
water and algae blooms have regularly been seen since 1975 in the areas of the Adriatic Sea
off Emilia-Romagna (Viviani, 1981, 1983, 1988; Viviani et al., 1985), the appearance of molluscs
toxic because of DSP in 1989 and 1990 was not preceded or accompanied by evident
phenomena of this kind (Boni et al., 1992; Viviani et al., 1990).
The toxicity of mussels was correlated, in 1989 and 1990, with the presence of D. fortii,
D. sacculus, D. acuta, D. caudata, D. rotundata, D. tripos and species similar to D. acuminata
in quantities of 2,000 cells/litre and even only 40 cells/litre (Viviani et al., 1990; Boni et al., 1992).
These species of dinoflagellates had not previously given rise to mono-specific blooms, but their
presence had been detected by the analysis of the phytoplankton carried out by the Cesenatico
Centre since 1976. From the data on the presence of phytoplankton in the seawater off the coast
of Emilia-Romagna (Table 23) and in the hepatopancreas of mussels (Mytilus galloprovincialis)
it can be seen that there are many species of Dinophysis and that the toxic material is related
to the following species: D. fortii is dominant in June and July, D. sacculus in August and
September, D. fortii and D. caudata in October and November, D. tripos in December.
Table 23
Monthly distribution mean (cell/dm 3 ) of Dinophysis spp. along the
Emilia-Romagna coast during 1989 (Boni et al., 1992; Viviani et al., 1990)
Month D. acuminata D. caudata D. fortii D. sacculus D.sp. D. tripos
June
July
August
September
October
November
December
8
0
0
0
0
3
0
0
0
0
10
124
43
6
Also along French Mediterranean coast (Sete) in June 1989, during Dinophysis spp.
blooms the presence of DSP toxins in mussels has been reported (Lassus et al., 1991). In
addition few cases of poisoning due to ingestion of mussels contaminated by Dinophysis spp.
were encountered in the region situated outside the Etang the Thau (Thau Lagoon) (Leveau et
al., 1989).
136
130
0
90
148
89
29
16
0
640
615
80
11
6
8
80
0
90
0
6
0
32
50
0
5
48
54
63