Close-up in the laboratory of the top of incubation core tubes containing bottom sediments. The syringe is used to sample the overlying water during the incubation period. The concentration of solutes in the overlying water is used to provide time-series information on the change in concentration of solutes during the test. The concentration time-series data is used to determine the benthic flux of solutes from the sediments -- from the Benthic Flux of Dissolved Metals Photo Gallery