(Biological) Generally locations of high activity, or gathering areas, where animals feed and breed. Species diversity peaks globally at these distinct locations, often located at intermediate latitudes (20-30 degrees North and South) where tropical and temperate species overlap. Hotspots are usually located close to prominent marine geographic features, such as reefs or shelf breaks. These areas seem to be important for many species at once, from plankton to sharks. (Geological) Areas of the Earth's crust where jets of molten mantle material rise to the surface, forming new crust. One classic example of hot spot activity resulted in the Hawaiian Island chain.