“…The aquatic photosynthesis processes occur in the euphotic zone, the layer between the surface and the depth of 1% of the subsurface irradiance, and this layer can be thicker in clear waters and thinner in turbid ones (Bukata et al, 1995;Wozniak et al, 2003). Some instrumentation has been developed to measure the underwater radiance field in lakes, fjords and oceans (Sasaki et al, 1958;Jerlov and Fukuda, 1960;Tyler, 1960;Lewis et al, 2011;Antoine et al, 2013;Potes et al, 2013). In particular, Potes et al (2013) developed a new apparatus to be coupled with a portable spectroradiometer, allowing for spectral radiance measurements in underwater environments and to subsequently obtain estimates of the spectral and broadband light attenuation coefficients in water.…”