Many investigators have made population studies on the intertidal region, particularly to determine the zonation of marine life in correlation with tidal levels. These workers for the most part have adopted the commonly used square meter or square foot quadrat, or fraction of same, so successfully employed in the study of terrestrial populations. In some cases, such as extensive, gently sloping beaches and flats this method has been very satisfactory....
Dexter, Ralph W.. 1943. "A suggested counting frame for intertidal population studies." Journal of Marine Research 5, (2). https://elischolar.library.yale.edu/journal_of_marine_research/607