Scientists have investigated the effects of surface crude oil on the feather structure of the Manx shearwater (Puffinus puffinus), a species of seabird that spends a high proportion of time on the water surface. Surface oil as thin as 0.1 µm (micrometers) was enough to increase feather permeability, while greatest impacts on permeability were caused by exposure to dark color surface sheens 3 µm in thickness. Oil-damaged feathers of the Manx shearwater...