Here are entered works on groups of fish, all of the same species, that occupy a particular area. Works on groups of fish populations interacting and living together in a particular environment are entered under Fish communities.
Here are entered general works on overpopulation. Works restricted to overpopulation in a particular place are entered under the name of the place with the subdivision Population. Some general works on overpopulation cataloged before 1993 may be found under the heading Population.