ABSTRACT
Diarrhetic shellfish poisoning, caused by Okadaic Acid (OA), is a threat that can cause ecological changes and contribute to loss of investment in time, labour and feed in the aquaculture industry. OA is a potent inhibitor of phosphatase found in dinoflagellates and is associated with seafood poisonings. Vibrio harveyi is a luminescence bacterium found worldwide and it is the main cause of vibriosis, especially against shrimps and mollusks. This thesis aimed to establish whether okadaic acid would facilitate a Vibrio infection in Artemia. Brine shrimp Artemia are used for diet in larviculture of fish and shellfish, and they are proven to be model organisms for studies in ecological aspects. It was found that 50 nM and 100 nM concentrations of OA are lethal to Artemia, and 10 nM and 20 nM became lethal in the presence of Vibrio harveyi. Among different strains of V. harveyi, BB120 (wild type) was the only one that showed an interaction effect when combined with okadaic acid in 20 nM. The results show the importance of more studies investigating the effects and mode of action of marine biotoxins, especially considering how these threats could affect the aquaculture industry in the coming years.
