Effects of algal toxicity on the clearance rate of the blue mussel (Mytilus edulis)

Abstract

The purpose of this study was to investigate the effect of toxic strains of Karlodinium veneficum on the clearance rate of Mytilus edulis. Suspensions of the toxic strain and the non-toxic strain of K. veneficum, mixed with an alternative non-toxic species, Prorocentrum micans, were made and performed as parallel experiments in order to compare their effects on clearance rate. Clearance rate was measured by taking samples from suspensions every five minutes up to 30 minutes, and counting the algal cells found within each sample using a Sedgewick rafter slide. No significant difference was found between the two experiments (F (9.322, 79.237) =0.743, P> 0.05). Further tests were performed in order to test the effects of varying concentrations of toxic K. veneficum on the clearance rate of M. edulis. Analysis of these experiments also disproved the hypothesis, indicating an insignificant difference between experiments (F (2.962, 23.696) = 1.265, p> 0.05). Due to wide ranges of standard error within collected data, a control experiment was performed using no mussels in order to show that changes in algal concentration were in fact caused by mussel filtration and not sampling error. The results of this experiment were significantly different from those involving mussels (F (3.870, 61.926) =0.636, P> 0.05), proving that results were valid. As a result of analysis, the hypothesis of this study cannot be accepted, and further research is considered to be necessary.