engleski

SHELLFISH TOXICITY RECORDED DURING MONITORING PROGRAMME ON CROATIAN SHELLFISH FARMS DURING 2001

The monitoring programme was conceived as an effort to control shellfish breeding farms on the Eastern Adriatic coast. Mussels were collected from February 2001 to February 2002 and their tissue tested for biotoxins, such as Diarrhetic Shellfish Poisoning (DSP) and Paralytic Shellfish Poisoning (PSP). Therefore, information was collected on environmental parameters (oxygen saturation, salinity, temperature) and on the state of phytoplankton community in respective marine areas. The samples of Mytilus galloprovnicialis were subjected to the mouse bioassay on a monthly basis during the colder part of the year (from November to March) and on a fortnight basis (from April to November). The test was not positive for PSP but gave two positive results for the presence of DSP toxins. Some additional analyses (Protein Phosphatase Assay) showed the presence of okadaic acid (OA) in those samples, even though their concentrations were very low. The studies demonstrated the widespread (in all shellfish-breeding areas) but occasional presences of potentially toxic phytoplankton organisms (Dinophysis fortii, D. acuminata, D. acuta, D. sacculus, D. caudata, Prorocentrum minimum, Lingulodinium polyedrum, Pseudo-nitzschia complex). Their abundance was higher in the breeding areas of the northern part of the study area than in its southern part. Undoubtedly, the highest number of potentially toxic species and their higher abundance were recorded in the warmer period of the year (from April to November).

toxic phytoplankton; DSP; Dinophysis spp.; Adriatic Sea

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