Monitoring of the shellfish biotoxins

Monitoring of the shellfish biotoxins

Natural biotoxins (phycotoxins) are planktonic algae

Natural biotoxins (phycotoxins) are planktonic algae products that are produced to defence against predators. Bivalve shellfish can accumulate large quantities of biotoxins by water filtration. In humans, these toxins can cause six syndromes: ASP, AZP, DSP, NSP, PSP and VSP (see next paragraph).  Detection of biotoxins is carried on HPLC (High- Performance Liquid Chromatography) with different detectors.

In the coastal waters of Montenegro, biotoxins monitoring started in 2014, but IMB (Institute of Marine Biology of Montenegro) working team performs regular monthly monitoring of toxic and potentially toxic algae species for years. In neighbouring countries, primary Croatia and Italy (FVG Region and Emilia Romagna Region), permanent marine biotoxins monitoring is performed per years as well as for toxic algae species.

Although shellfish are healthy food, because of the potential presence of biotoxins can be a threat to human health. Marine biotoxins can occasionally contaminate some species of seafood. There is Europe-wide legislation that limit biotoxins levels in seafood that is put on the market. For more information, see the Commission Regulation 853/2004 as amended (see in particular Chapter V, Section VII in Annex III of the Regulation). The methods used for determining the toxins are described in Annex III of Regulation 2074/2005.

Because of that, it is necessary to introduce and apply the European Legislation about biotoxins control also in shellfish meat in Montenegro. Based on knowledge about toxic algae species that are present in the Boka Kotorska Bay, four types of poisoning can occur: amnestic poisoning, diarrhetic poisoningparalytic poisoning and venerupin poisoning. At the moment official data about poisoning in humans by biotoxins in Montenegro does not exist, but it is possible that some kinds of poisoning were mistaken with bacterial and viral infections because the clinical picture of these diseases is quite similar.


Biotoxins monitoring in Montenegro

In the coastal waters of Montenegro, biotoxins monitoring started in 2014 thanks to the support by the Ministry of Science of Montenegro and HERIC project through the BIO-ICT Centre of Excellence work.

 Monitoring included shellfish farms in Boka Kotorska Bay by Centre for Eco-toxicological Tests (CETI), Institute for Marine Biology (IMB) conducts biotoxins monitoring in the framework of the Center of Excellence in Bioinformatics (BIO-ICT). Sampling began in November 2015 and will last for the next two years. Sampling is done on three farms in the bay as well as one point on the open sea. Monitoring covers the detection of ASP and PSP groups of toxins using a liquid chromatography. Sampling, transport, processing and preparation of solutions for liquid chromatography are made under the rules of the Community Reference Laboratory on Marine Biotoxins.

 For detection of ASP toxins group protocol according to Qualliam et al. (1995) is used, while for PSP toxins groups AOAC Official Method 2005/06 is used. IMB working team also performs regular monthly monitoring of phytoplankton community in the bay in order to monitor toxic and potentially toxic algae species. Due that biotoxins are dangerous substances in humans, their control, especially on shellfish farms, is of great importance in terms of food safety. 


Shellfish farms in Boka Kotorska Bay

Boka Kotorska Bay is quite isolated and closed basin with specific climatological, hydrological and hydrographic characteristics. By geographical and hydrographic characteristics the bay can be divided into three sections: Kotor-Risan bay, Tivat Bay and Herceg Novi Bay.

 Each part is characterised by a relatively large depth. The flow of fresh water from the atmosphere, land and marine resources is extremely large and as such have a positive influence on eutrophication reducing. The water flow is expressed mainly at depths up to 5 m and is most intense during the maximum flow of fresh water. Managing the flow of current has output direction. Temperature, salinity and density of sea water are greatly influenced by hydro-meteorological parameters that are specific and subject to frequent local changes. Therefore, stratification of these parameters is not subject to the rules of the open sea.

 There are sixteen shellfish farms in Boka Kotorska Bay, with a total annual production of 150-200 tonne. Mussels farming is done on floating parks and breeding technology is reflected in two steps: adoption of acceptance spawn on collectors, sorting and seeding. Spawn younger adoption take about eight months. The seeding of mussels - first dressing, is best to be done in late September or March. After this step mussel spends 6-8 months in water. Individuals who are in the first finishing reached a length of about 4-5 cm, are placed together and return to the water for next 6 months. After a total period, about 20 months, mussels reaches market size and can be placed on the market. The size of market mussels shall not be less than 5 cm (Anonymous, 2010). There are also fish farms in Montenegro: trout (annual production around 450 tonne), carp (annual production around 5 tonne), sea bream and seagrass (annual production around 50 tonne) (Mandic and Huter, 2014).

Patricija Muzlovic, Tanja Knezevic




Related questions

No questions published yet related to these topics.