Mixing layer running incubator (MIRI): an instrument for incubating samples while moving vertically in the mixing layer

Research on the impact of natural radiation on aquatic biota requires novel instruments and methods enabling realistic tests of the effects of changing radiation on communities. This article describes an instrument devised to expose samples maintained in incubation flasks to the variable conditions experienced by the water masses in motion in the mixing layer. This apparatus can be useful to measure the biological processes occurring in the photic zone of aquatic ecosystems avoiding the bias due to the incubation at fixed depths. Here an example of its use is presented, comparing the effect of photosynthetically active radiation ( PAR) and ultraviolet radiation (UV-R) in samples incubated at fixed depths and using MIRI (MIxing layer Running Incubator).