Habitat fragmentation describes the emergence of discontinuities or fragmentation in an organism’s native environment, causing population fragmentation and ecosystem decay. It is a process during which a large expanse of habitat is transformed into a number of patches of a smaller total area, isolated from each other by a set of habitats unlike the original. It increases discontinuity in the spatial patterning of resource availability, affecting the conditions for species occupancy, and ultimately individual fitness. Fragmentation can arise via both natural and anthropogenic processes in terrestrial and aquatic systems.