Genesis and evolution of polarization of light in the ocean [invited].

The radiative transfer of sunlight through the deep oceans of the world is a complex and only partially solved environmental optical problem. Empirically, in situ systematic measurements of key parameters such as polarization of deep open seawater have been very sparse in recent decades. Although we have the necessary equation of transfer to solve this complex problem, until it can be solved explicitly, only approximations and partial analytic solutions are possible in addition to some successful computer modeling. Further complexity is added by the diversity of researchers' interests from academic to international policy making, as well as the ineffective communication between the different disciplines concerned, ranging from mathematics to endangered species. As a result, isolated focused pockets of good data and theory have been developed in recent decades without the needed breadth of understanding. This present review intends to bring together some visual biology and optical physics in order to understand the role of polarization in navigation, communication, and identification of marine animals as well as a possible tool for remotely sensing underwater objects.