“Pixels May Lose Kelp Canopy”: The Photomosaic as Epistemic Figure for the Satellite Mapping and Modeling of Seaweeds

This article shows how the photo-mosaic characterizes epistemic practices in contemporary oceanography, particularly through the satellite survey and ecological modeling of marine macroalgae (seaweeds). Drawing on John Murray’s 1912 formulation that oceanographic knowledge relies “upon a patiently put together mosaic representation of the discoveries” and Nancy Cartwright’s description of theory in science as a patchwork, I examine the mosaic as both an organizational form for oceanographic knowledge-making and as an aesthetic that emerges in remote surveillance. Through a comparative analysis of the visual and computational media surrounding sargassum and giant kelp, I analyze how a photo-mosaic epistemics and aesthetics emerges through the squareness of pixels and mapping interfaces, and through the ways that discrete instances of sampling and observation are assembled into provisional pictures of understanding. Moreover, I argue that the visibility of sargassum and giant kelp to a satellite depends on what I call their “photo-availability,” or the physical and metabolic qualities that make them sensible to satellite detection. In this way I consider seaweeds as active agents in the distributed media system of satellite imaging, rather than the passive objects of surveillance and monitoring, where epistemic mosaicking emerges as a strategy for knowledge and control.