Surface waves are significantly damped by biogenic surfactants which accumulate at the ocean's surface from the high latitudes to the tropics. The growth, development, and breaking of short wind-driven surface waves is a key mediator of the air-sea exchange of momentum, heat, and trace gases; consequently, the effect of surfactant compounds in the uppermost millimeters of the ocean in damping short surface waves bears on earth's climatic processes. The mechanisms through which surfactants suppress waves have been studied in great detail through careful laboratory experimentation in quasi one-dimensional wave tanks. However, the spatial scales over which this damping occurs in structurally complex surfactant slicks on the real ocean have not been resolved. Here we present the results of field observations of the spatial response of decimeter to millimeter-scale waves to biogenic surfactant slicks. We found that wave damping in organic material-rich coastal waters resulted in a net (spatio-temporally averaged) reduction of ~50% in momentum input to the wave field relative to the open ocean for low to moderate wind speeds. This significant effect had thus far evaded quantification due in large part to the enormous range of scales required for its description-- spanning the sea surface microlayer to the ocean submesoscale. These results are of critical importance to describing the energy exchange between ocean and atmosphere and in forecasting the coupled earth system.