littoral zone The littoral zone is the part of a sea, lake, or river that is close to the shore. The adjacency of water has many consequences including the generation of microclimates and impacts on the biology. This class is intended to capture littoral zones that are associated with marine, freshwater, and any other aquatic environments. Note that there is no single definition of the extent of the "littoral zone", associated with any water body. Here, we use definitions that will be more familiar to marine biologists rather than military organisations, although the latter can be added on request. environmental zone