The Gulf of Finland, the Bothnian Sea, Northern Baltic Proper

Concentration of phycotoxins in biota

Observers

The data set consists of results on algal toxin concentrations in phytoplankton, fish and molluscs. Cyanobacterial hepatotoxins have been analysed in all matrices, the DSP toxin okadaic acid only from mussels and flounders from 1993 and 1996. Phytoplankton was collected from onboard the R/V Aranda or from motorboats. Fish (flounders, salmons, herrings, cods, sticklebacks) were caught with usual fishing nets by fishermen and molluscs collected by SCUBA divers. The samples were freeze-dried and extracted with either water/methanol/n-butanol or 100% methanol. Analysis of extracts was carried out using high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay (ELISA), or combination of these two. Okadaic acid was detected in some of the flounders and blue mussels (1993 and 1996 respectively). Cods, herrings and salmons (all areas) have contained only trace amounts of cyanobacterial hepatotoxins, whereas hepatotoxin concentrations in flounders and blue mussels (both from the Gulf of Finland) have reached 0.4 and 2.2 mg/kg respectively. These two species continuously accumulate hepatotoxins with peak concentrations in August-September. Three-spined sticklebacks have contained ca. 40-170 mg/kg of hepatotoxins. Phytoplankton containing Nodularia spumigena filaments has constantly contained ca. 0.1-10 g/kg of hepatotoxic nodularin.

Finnish Environment Institute
Latokartanonkaari 11
Helsinki

00790
Finland