A Pilot Study on the Effects of Temperature on the Blooms of the Benthic Mucilage-Forming Microalga Chrysophaeum taylorii

Abstract: C. taylorii ( Chrysophaeum taylorii ) Lewis and Bryan ( Pelagophyceae ) are benthic mucilage-producing microalgae recently recorded in the Mediterranean Sea, where its summer blooms are having detrimental effects on benthic communities, fisheries and tourism, especially along the Sardinian coasts (western Mediterranean Sea). Although few informations on the bloom dynamics of this microalga are available in literature jet, recent studies have hypothesized that sea water temperature plays a major role in determining the distribution and abundance of C. taylorii . The goal of this pilot study was to verify the above-mentioned statement providing experimental evidence for it. To this purpose, C. taylorii presence and abundance were investigated along a temperature gradient near the powerhouse of Torre Valdaliga (Latium coasts), where a stream of hot water is continuously pumped out from the powerhouse into the sea. The obtained data showed that C. taylorii abundance was significantly higher in the study sites nearer to the powerhouse and a positive correlation between water temperature and cell densities was found, thus confirming that water temperature is one of the environmental variables directly influencing the bloom dynamics of this microalga in the Mediterranean Sea.