Effect of thymol on invasive golden mussel “Limnoperna fortunei”

MIRTA STUPAK, MÓNICA GARCÍA, MIRIAM PÉREZ, GUILLERMO BLUSTEIN

Newcastle University, United Kingdom

Congreso; 15th International Congress on Marine Corrosion and Fouling (15th ICMCF); 2010

Newcastle University

The studies on freshwater biofouling in Argentina gained importance in the last two decades, due to the invasion of Limnoperna fortunei (Bivalvia, Mytilidae), an Asiatic mollusk that colonized rapidly hard substrates of Rio de La Plata basin generating a diversity of inconveniences not recorded before.  Recently, the use of natural products with antibacterial properties has been applied to interrupt the first stages of fouling sequences.  In this study, we evaluate the effect of thymol, a major component of thyme essential oil, on the settlement of Limnoperna fortunei in the laboratory.  Adult mussels were exposed to solutions of thymol ranged between 1 and 250 µM. Both, byssus number formation and mussel survival for 48 hours were recorded. Recovery tests were carried out in order to determine whether thymol acts through a temporary or a permanent mechanism. Finally, toxicity tests were conducted on a non-target organism, the native gastropod Heleobia piscium.  The results indicate that thymol significantly reduces the formation of byssal thread number at concentrations over 10 ìM (p <0.05). The concentration that inhibits the activity of 50% of the population (LC50) was 22 ìM. However, treated organisms recovered their ability to produce byssus when they were transferred to clean freshwater. No effects on survival and/or behavior of the gastropod Heleobia piscium were registered.  In conclusion thymol inhibits reattachment of mussels by a temporary mechanism. Therefore, it is a promising compound to control Limnoperna fortunei settlement.