Animals and plants have close relationships with the bacteria on their surfaces and macroalgae — like kelp — are no different. The spatial structure of these microbial communities can impact how they interact with their neighbors, host, and environment. A recent study used spectral imaging to characterize the spatial structure of the bacteria on Nereocystis luetkeana. The kelp hosted a dense microbial biofilm that consisted of closely associated, but diverse, microbial taxa. For example, Gammaproteobacteria were found close to the kelp surface, and filamentous Bacteroidetes and Alphaproteobacteria were concentrated near the biofilm-seawater interface. Bacterial density also varied along the length of the kelp blades with density increasing from new tissue at the base to older tissue at the blade tips. Between kelp populations, declining populations hosted fewer microbial cells than kelp from a stable population. This study characterized the dense, spatially differentiated community on N. luetkeana and contributes to our mechanistic understanding of the kelp microbiota. This kind of mechanistic understanding can be applied to macroalgae management in both conservation efforts and aquaculture.