Most species of anurans require ponds for reproduction. This book discusses the attributes likely to influence a pond's suitability as a spawning site include factors such as vegetation, depth, water chemistry, presence of predators, hydroperiod and water chemistry. But in many landscapes, the availability of suitable ponds is limited. This book also discusses recreational and commercial pond usage in the south-eastern United States, which influences nutrient and fish production making the ecological role of shallow lakes and ponds among the most threatened habitats in the world. Also explored are lakes and ponds beyond the Earth, such as the dry lakebeds on Mars and active methane-ehtane ponds on Titan, and the behaviour of boundaries between gradient zone and convective zones in a salinity gradient solar pond.