A influência do fitoplâncton na propagação acústica submarina

Abstract

The organisms of phytoplankton that lives in the fresh, brackish or salt water. They play an important role in the physical environment such as blocking sunlight, chemical variations in the water and so on. Additionally , there are evidences that phytoplankton behavior may affect small scale viscosity, although its variation is mainly due to temperature and salinity. Several authors pointed out that biological factors may also affect directly water viscosity and, conseque ntly, influence sound propagation at sea. However, phytoplankton role in sound attenuation still needs to be better understood. Recent studies highlight the potential of some species of modifying the physical properties of the ocean and, hence, affect unde rwater acoustic propagation conditions. Thus, this study demonstrates the effects of phytoplankton presence in this propagation. Nannochloropsis oculata was selected for the acoustic experiments in the tank in order to evaluate propagation loss in three un derwater environments fresh water, salt water and salt water with phytoplankton simulating a fast growing scenario of these organisms (bloom).