Abstract
Diarrhetic Shellfish Poisoning (DSP) toxicity was revealed in the Mediterranean blue mussel (Mytilus galloprovincialis) from the Bay of Mali Ston, in the south part of the Eastern Adriatic Sea, through the Croatian National Monitoring Programme in the period from January until June of 2011. A survey of DSP toxicity within the frame of regular controls carried out through the mouse bioassay (MBA, at the time the official method for DSP toxins) demonstrated that in some incidents, positive MBA, which manifested by the atypical symptomatology of the animals, dominated. Additional studies were done to explain the atypical results of the conducted biological tests at the time. In the current study, the bioaccumulated manganese concentration in the soft tissues of mussels was measured to investigate its influence on the MBA results. In both DSP negative and DSP positive samples, which were prepared for the analysis according to the modified US EPA 3052 method, the concentration of the bioaccumulated manganese was performed on the atomic absorption spectrometer using flame atomic absorption spectroscopy technique. The analysis revealed higher concentration of manganese in 87% of DSP positive samples and the expressed per wet weight ranged from 0.15 to 5.38 mg kg−1. The mean concentration of manganese for all DSP positive samples was 1.78 mg kg−1, while for DSP negative samples, it was 48% lower (0.93 mg kg−1). The highest concentration of manganese in DSP positive samples was measured in February 2011. Since the low concentrations of lipophilic biotoxins gymnodimines (GYMs) and spirolides (SPXs) were also detected in the analysed DSP positive samples in the parallel studies, the results obtained in this study suggest future investigations of the connection between the concentration of manganese and lipophilic biotoxins.
Highlights
Due to their characteristics such as wide geographic distribution, sessile lifestyles, ease of collection, and accumulation of various environmental contaminants, shellfish are often used as biological pollution indicators of coastal areas
Positive samples) of blue mussels (M. galloprovincialis) gathered from the farming area in the Bay of Mali Ston located in the southern Adriatic Sea weekly or more frequently if the results of mouse bioassay were positive
Mn concentrations in Diarrhetic Shellfish Poisoning (DSP) positive samples were in the range of 0.15 mg kg−1 to 5.38 mg kg−1
Summary
Due to their characteristics such as wide geographic distribution, sessile lifestyles, ease of collection, and accumulation of various environmental contaminants, shellfish are often used as biological pollution indicators of coastal areas. Shellfish feed on plankton by filtering seawater and can accumulate many ingredients such as toxins produced by toxic plankton, trace metals, organic contaminants, or dangerous microorganisms, often without any changes in their flesh’s appearance, becoming the cause of the potential consumer poisoning [1]. Due to the concerns over shellfish bioaccumulation and possible toxic effects on humans consuming these organisms, monitoring programmes have been widely established. Metals and marine biotoxins in shellfish have been implemented and carried out parallelly. Some of those studies pointed out the influence of trace metals and algal toxins, gymnodimines (GYMs), and spirolides (SPXs) on the false-positive results of the mouse bioassay (MBA) [2,3,4]. Trace metals can enter the sea from a variety of natural (by breaking rocks, through soil erosion) and anthropogenic sources (through mines or quarries, or through domestic, industrial, or agricultural discharges) and be bioaccumulated in aquatic organisms [5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
