We are continuing our work started under the Toyota Tapestry grant by abserving the salinity of Mobile Bay using data bouys we construct. We will see what changes there are in the system compared to a study by the federal goverment done twenty years ago. Salinity changes can affect the entire ecosystem. It will be interesting to see if there have been fundamental changes due to the surrounding area development. We will take two approaches to the instrumentation for measuring salinity. Our first approach depends on the measurment of conductivity and temperature. This will avoid errors in conductivity which are almost unavoidable using electrical detection.