Geological, chemical, or hydrodynamic features that are ecologically important or influence patterns of human uses of the ocean. Examples include seamounts, persistent upwelling zones, areas of low dissolved oxygen, and areas of reduced pH. Distributions are recorded observations of parameters and features, often as a function of time as well as place, also including maps and three-dimensional predictions of distributions based on combinations of observations and theory. Distributions of physical and chemical features (for example, physical habitat, substrate, or bathymetry) are often used as data to support habitat-biota models. Assessments provide information about the value, impact, drivers, connections, or functions of a feature in its present distributions, or they evaluate the effects of physical/chemical features on ecology or suitability for use. Assessments can include climate change models that project environmental effects of climate change and acidification. Larger assessments that combine physical/chemical features with other Resources and Uses categories can appropriately be included here and also in the other related Resources or Uses categories. Predictions are the results of models or projections of future distributions, values, or impacts, which include anticipated changes produced by natural and human processes, and they are also the results of scenario-testing models for comparing outcomes of different management actions.